Handheld Devices
Quick, reliable and easy measurements in the field or laboratory
Service support

At PSI we are committed to provide our customers with the best possible IT and systems support. Our support team is highly trained, professional and our goal is to ensure we fix your problem as soon as possible.

Support email: support@psi.cz

Sale terms
  • Pricing and availability are subject to change without notice. Quotations are available upon request. All prices are based upon a single item purchase unless otherwise noted. All customers are afforded the same pricing as the current price list. Quantity discounts are determined by PSI Management.
  • Quotations for PSI instrumentation always include pricing, delivery information, validity from the date of issuance, and bank details. Prices do not include shipping and packing costs; those are added as a separate item on the invoice or on the quotation. Prices exclude VAT.
  • Customs clearance and all duties are not the supplier’s responsibility.
  • Custom or special-made equipment is nonrefundable and nonreturnable. It is warranted for workmanship only – PSI cannot guarantee that it will work for the customer’s special purpose.
  • Purchase Orders must include a complete invoice address and shipping address and precise description of ordered items. Once a customer’s purchase order is submitted and accepted, PSI recognizes a contract with the customer for goods to be supplied. PSI is not responsible if shipping date must be extended longer than it was originally quoted (due to unforeseen happenings, such as year-end closing, fiscal year closing etc.). Alteration or cancellation of the purchase may result in additional charges or penalties. PSI is not responsible for items that were ordered incorrectly.
  • Wire transfer is the preferred payment method. It is the quickest and least expensive way to pay for your order. If you have a Quotation or an Invoice from us, that is all that your bank needs to make an electronic money transfer. PSI bank information for wire transfer is provided on the Quotation/Invoice. Please include your name and our Invoice/Quote number in the Wire Transfer reference.
  • Check may be accepted ONLY upon prior approval.
  • Credit card may be used in our Credit Card Payment Gateway. For details, write to ivana(at)psi.cz.
  • Letter of Credit or CAD are unusual form of payment for PSI. Customers wishing to pay by Letter of Credit or CAD must alert PSI about this intent upon submission of the purchase order. PSI will furnish these customers with additional terms and conditions specific to the issuance of the Letter of Credit or CAD. L/C content or CAD content must be agreed by PSI prior to their issuance. Both Letter of Credit and CAD administration fees are EUR 500. For details, write to ivana(at)psi.cz.
Shipping policy

Shipping Policy

READ the following instructions before you accept the shipment from the carrier.

  • Inspect the shipment carefully.
  • If you received an evidently damaged shipment, do not accept it from the carrier.
  • If there is no visible damage, open the container and check its contents carefully.
  • It is the customer's responsibility to unpack the parcel and to check its content within 48 hours after delivery. If the damage claim is reported after this time period, PSI will not be able to claim for refund for damaged goods at the shipping company. In such case, any future repair to the damaged goods will be considered as non-warranty repair.
  • If any damage is found in the parcel content within 48 hours after delivery, please contact PSI – support(at)psi.cz.
  • All PSI shipments include a list of shipped instruments and/or additional parts. Please, compare the contents of the shipment and the enclosed list.
  • If concealed damage is found after the shipment is opened, make a written note of any damage (on wrapping, container, contents, etc.) and send it to the carrier and to PSI.
  • Retain all shipping materials for the purpose of damage inspection.

Goods shipped by PSI were delivered to the carrier in good condition. They were packed with great care using standard approved packaging methods. All PSI shipments are insured for the full product value and the carrier is responsible for any damage in transit! Please, report any damage or incomplete shipment to PSI immediately.

E-mail: shipping(at)psi.cz
Phone: +420 511 440 549
Fax: +420 511 440 901

Return Procedure

Before returning any instrument to PSI:

  • Make sure that the instrument is in fact faulty and has not just been set up improperly.
  • Contact PSI support(at)psi.cz before sending anything back. You will be given the RMA number, which must be clearly marked on the outside of the shipped container.
  • When sending the faulty device back to PSI, please pack it very carefully. Use a have duty box and lots of wrapping/foaming material.
  • If the returned instrument is damaged during shipment due to insufficient packing, PSI will have to charge the repair (or its part) as a non-warranty one.
  • If you have encountered a program failure, we would need a printed copy of any faults you have seen, including how to reproduce them. Include it into the return package along with your mailing address.
  • Include a copy of the Invoice on which the product was shipped to you.
  • All returns must be shipped prepaid. Unpaid packages will not be accepted.
  • In case of questions contact us by E-mail: support(at)psi.cz or shipping(at)psi.cz, by phone: +420 511 440 034, +420 511 440 032,+420 511 440 022, +420 388 440 046, or by fax: +420 511 440 901.
FAQs
FAQs
General questions
  • Is the FluorPen software capable of recording used light intensitis?
  • Unfortunately no.
  • Is there a function "RESET TO FACTORY SETTINGS" in the FluorPen software?
  • Unfortunately, there is no such function in the FluorPen software. The only possibility is to reload the device firmware, which we recommend just in emergency cases.
  • When the instrument is set for fluorescence measurement, there is a writing beneath which reads "low val". What does it mean?
  • “Low val” means low value of fluorescence signal. Samples with very low concentration of chlorophyll show low fluorescence signal.
  • Where can I check FluorPen/Spectrapen software compatibility with different Windows versions?
  • It can be checked at our web page http://psi.cz/downloads/
  • Is my device equipped with both USB and Bluetooth communication?
  • No, the device always comes with just one communication module - either USB or Bluetooth. But the new 110-X series (released during 2018) will have both communication modules.
  • I have a device with USB communication and I need to download measured data to a computer. However, the computer does not recognize that the device is connected. Can you help on this?
  • For USB connection you need to have the USB driver installed in your PC. You find the driver on the installation disk (USB driver folder). If you check the Device Manager in Windows you should see the USB serial port in the device tree. In case of missing driver you may download it from the following link: http://www.psi.cz/ftp/…..Pen/USB_Driver_Setup.exe When the driver is installed correctly you should be able to connect to the device in the FluorPen software menu Setup->Device ID.
  • Referring to the GPS Module - what is the accuracy of the location registration?
  • It is a standard GPS with accuracy of +-2m. Current accuracy is influenced by signal strength and it is shown on the GPS device.
  • I have a device with USB communication. I transferred the measured data to a PC via the FluorPen software. Now I am trying to save or export it to txt format, but the Export icon at FILE menu is not functional (disabled ). Do you have an advice to enable the key and its function?
  • You need to activate the software by entering the serial number. You can do it in the menu Help-Register. Your serial number is on the installation flash drive in the SN.txt file. The procedure is also described in the user manual.
  • What should I do when the display on my device shows just FP-Boot and 1.0.0.0 when switched on and does not do anything after that?
  • Please update the firmware with the BXN file. Update procedure: (1) Connect the device to the PC; (2) Select menu Setup->device ID; (3) Select menu Setup->Update firmware from file; (4) Select the downloaded BXN file. Firmware updating procedure is also depicted in the Operation Manual.
  • We are unable to download the data from the device to the Excel spreadsheet: please, could you tell how can I do?
  • In the Fluorpen software go to Export and export the data to txt file. Then in Excel go to Data and Import Data from Text. In this way you export data directly to Excel and process then further. You can find more information on how to do it for example here.
  • Is it possible to export just part of measured data or all data must be exported?
  • It is possible to export all data or one selected measurement. Mark the selected measurement by mouse before export. Then go to Export menu and choose Selected only.
  • What is the purpose of the PAR sensor (Light Meter) ?
  • Integrated Light Meter serves for direct digital readouts of Photosynthetically Active Radiation (PAR) in the range from 400 to 700 nm, the span in which plants use energy during photosynthesis. PAR is measured as Photosynthetic Photon Flux Density (PPFD), which is indicated by units of quanta (photons) per unit time per unit surface area. The sensor has a uniform response to photons within the 400 - 700 nm waveband.
  • Can you shortly explain the difference in between the PolyPen RP 410, SpectraPen SP 110 and SpectraPen LM 510 ?
  • PolyPen RP 410 measures reflectance on leaves or other plant samples. It is capable of calculation of various reflectance indices (some of them are pre-programmed). It features an integrated light source and a leaf clip. SpectraPen SP 110 is a spectrometer without spectroradiometric calibration. It features a SMA905 light fiber port. It is intended for measuring reflectance, transmitance and light wavelength. SpectraPen LM 510 is a spectroradiometrically calibrated spectrometer with integrated cosine corrector. It measures absolute values of light intensity in uW/cm2/nm and photon flux density in umol/m2/s/nm. It calculates: irradiance (uW/cm2/), PAR (umol/m2/s), illuminance (Lux), CIE1931 coordinates, CCT (L).
  • Is there any difference in measuring absorbance and transmittance with the PolyPen and with the SpectraPen?
  • PolyPen is equipped with an internal light source. Thus it is a complete system for leaf reflectance measurements not requiring any additional accessories. SpectraPen is a simple spectrophotometer with no in-built light source.
  • We have a problem to activate the external GPS Module. How can we activate it?
  • Please check the Manual provided. To correctly attach the GPS coordinates, it is essential to set time correctly on the device and on the PC. It is using time zone settings from the computer so you should check that too. Also check that Garmin is set in Mass Storage mode.
FluorPen
  • What is measuring time of the FluorPen protocols?
  • It differs for single protocols: Ft takes about 100 ms, OJIP and QY about 1-2 seconds, NPQ and LC protocols take up to few minutes.
  • Is it possible to calculate ETR from data measured by the PAR-FluorPen?
  • Yes, it can be calculated by the Light Curve data using this equation: YII*PAR*0.84*0.5.
  • In which units is measured fluorescence in FluorPen devices?
  • Fluorescence is measured in relative fluorescence units, also called arbitrary units (A.U.).
  • I have a problem downloading data from our FluorPen. When the device gets to the end (100%) of the download, it gives an Error: TFpData:parse Data0 -> unknown ID 0. And then just sits with the spinning circle and there is no way to get data off the unit.
  • This error means that the data in internal memory are corrupted. The reason for that could be for example power failure (battery dead or removed) during data saving procedure. If there are no important data it could be easily solved by erasing the memory.
  • Can I measure Ft and QY in presence of light (without dark condition)?
  • Basically all measured fluorescence parametres can be acquired either after dark adaptation or in the light adapted state. Ft refers to Fo if the leaf sample is dark-adapted (Fo refers to minimal level of fluorescence in dark adapted state). QY measured in the light is equal to Fv´/Fm´ and it provides an estimate of the PSII maximum efficiency within light-adapted material in contrast to Fv/Fm which is an estimate of the PSII maximum efficiency within dark-adapted material. Explanation of particular parameters: Fo - minimum fluorescence signal (when all PSII centres are in the open state) from dark-adapted material; Fo' - minimum fluorescence signal (when all PSII centres are in the open state) from light-adapted material; Ft - fluorescence signal at any point between Fo' and Fm', in other words instaneous fluorescence which is affected by the level of light the object is exposed to; Fm - maximum fluorescence signal (when all PSII centres are in the closed state) from dark-adapted material; Fm' - maximum fluorescence signal (when all PSII centres are in the closed state) from light-adapted material.
  • Is it good to measure dark-adapted samples?
  • It is recommended to measure dark-adapted samples. The dark-adaptation guarantees the same starting conditions before measurement of samples cultivated in different conditions. But what is more important you get better results (= higher photosynthetic performance), because in dark all reactions centers of PSII relax and are ready for incoming light energy. In light-adapted sample some of the reaction centers are saturated with the ambient light and therefore cannot accept all photons of the incoming light and you get lower QY value. You could of course compare QY values of light-adapted samples, but the result could be affected by light conditions before the measurement.
  • How long dark-adaptation time is recommended?
  • Duration of dark adaptation depends on species, in general it is between 5 and 15 minutes.
  • Do the Ft values change within one measurement or between measurements? Should I do some kind of calibration or programming before measuring?
  • The value can change slightly (in range 10%). If the change within one measurement is bigger, it is recommended to set the f_pulse intensity lower. Strongly increasing Ft value within one measurement means, that f_pulse is too strong and causes unwanted "actinic effect" (= photochemistry starts). Fluorescence measurements do not require calibration.
  • Can you explain meaning of the 'f_pulse' in the FluorPen device?
  • This function serves for setting of measuring pulses intensity. The measuring pulses are weak pulses, which are able to induce the minimal chlorophyll fluorescence (Fo or Ft). It takes only 30 µs and the maximum intensity is 3000 µmol photon.m^-2.s^-1. It means 30 µs * 3000 µmol photon.m^-2.s^-1 = 0,09 µmolphoton.m^-2 per pulse is the maximal intensity of the f_pulse.
  • Can you explain meaning of the 'F_pulse' in the FluorPen device?
  • This function serves for setting intensity of the saturating pulse. Saturating pulse is able to induce maximum chlorophyll fluorescence (Fm). 100% of intensity equals approximately 3000 µmol photon.m^-2.s^-1.
  • Can you explain meaning of the 'A_pulse' in the FluorPen device?
  • This function serves for setting intensity of measuring pulses. Actinic light is basically the ambient light in which the plants are growing. 100% of intensity equals approximately 1000 µmol photon.m^-2.s^-1.
  • In the FluorPen, Fv/Fm, Fv'/Fm' and qP from the OJIP test, I can easily have the Fv/Fm value. Then for the Fv'/Fm' (thus the light adapted quantum yield of PSII) which values should I use (is it calculated or not)? Also for the qP (proportion of open PSII, [Fm'-Ft/Fm'-Fo']) is there any value coming out from the tests or should I calculate it by myself (or from the NPQ test?)?
  • During OJIP curve measurement you do not use any light adaptation phase and therefore it is not possible to obtain PSII efficinecy in light adapted state and qP. OJIP is fast measurement of variable fluorescence transient during saturation pulse. To obtain Fv'/Fm' and qP you will need to use either Light Curve protocols or NPQ protocol.
  • We carried out several NPQ tests, but from the FluorPen datasheet I am not able to discriminate which is the NPQ value (Fom-Fm')/Fm'. Please could you explain to me a bit better what the data sheet from the NPQ means?
  • There are quite some explanations regarding each of the protocols available in the Fluorpen in the manual. For the NPQ you should refer to the page 35. You can find also description of the parametres measured and calculated. NPQ is calculated as (Fm – Fm_Ln) / Fm_Ln. You obtain NPQ value calculation for each of the Fm´value measured by saturation pulse during light and dark adapted state.
  • Should the Light Curve and OJIP protocols be done after a dark adaptation?
  • It is recommended to dark-adapt the samples before the chlorophyll fluorescence measurement. Duration of adaptation depends on the plant species, but in general 15 minutes should be sufficient. More information about the NPQ protocol can be found in the Operating Manual, page 32 – 36. Here are explained all parameters of this protocol. OJIP measurement reflect the chlorophyll fluorescence induction kinetics. O, J, I, and P steps correspond to the redox states of PS II and PS I and to the efficiencies of electron transfer through the intersystem chain to the end electron acceptors. If you want know the efficiency of the photosystem, you should better measure the Fv/Fm parameter.
  • In the FluorPen, I run few light curve tests (is the only one where I can see the Ft value): now, to calculate the ETR, I used the YII*PAR*0.84*0.5 equation (thus is giving me the response curve). Is that right? Thus, should I use the QY L value at each step (1-2-3 etc.) for each light intensity (i.e. for LC 2 is 0, 100, 200,300,500,1000 referring to QY max, QY L1, QY L2, QY L3 etc.)?
  • Exactly, the QY_Lss (YII) is calculated as (Fm_L – Ft_L) / Fm_L . ETR is calculated exactly as you wrote: YII*PAR*0.84*0.5.
  • How big is the memory in FluorPen device? How many OJIP curves can be saved in the device internal memory?
  • About 1100 OJIP curves can be saved at one time.
AquaPen
  • What is measuring time of the AquaPen protocols?
  • It differs for single protocols: Ft takes about 100 ms, OJIP and QY about 1-2 seconds, NPQ and LC protocols take up to few minutes.
  • In which units is measured fluorescence in AquaPen devices?
  • Fluorescence is measured in relative fluorescence units, also called arbitrary units (A.U.).
  • I have a problem downloading data from our AquaPen. When the device gets to the end (100%) of the download, it gives an Error: TFpData:parse Data0 -> unknown ID 0. And then just sits with the spinning circle and there is no way to get data off the unit.
  • This error means that the data in internal memory are corrupted. The reason for that could be for example power failure (battery dead or removed) during data saving procedure. If there are no important data it could be easily solved by erasing the memory.
  • Can I measure Ft and QY in presence of light (without dark condition)?
  • Basically all measured fluorescence parameters can be acquired either after dark adaptation or in the light adapted state. Ft refers to Fo if the leaf sample is dark-adapted (Fo refers to minimal level of fluorescence in dark adapted state). QY measured in the light is equal to Fv´/Fm´ and it provides an estimate of the PSII maximum efficiency within light-adapted material in contrast to Fv/Fm which is an estimate of the PSII maximum efficiency within dark-adapted material. Explanation of particular parameters: Fo - minimum fluorescence signal (when all PSII centres are in the open state) from dark-adapted material; Fo' - minimum fluorescence signal (when all PSII centres are in the open state) from light-adapted material; Ft - fluorescence signal at any point between Fo' and Fm', in other words instaneous fluorescence which is affected by the level of light the object is exposed to; Fm - maximum fluorescence signal (when all PSII centres are in the closed state) from dark-adapted material; Fm' - maximum fluorescence signal (when all PSII centres are in the closed state) from light-adapted material.
  • Is it good to measure dark-adapted samples?
  • It is recommended to measure dark-adapted samples. The dark-adaptation guarantees the same starting conditions before measurement of samples cultivated in different conditions. But what is more important you get better results (= higher photosynthetic performance), because in dark all reactions centers of PSII relax and are ready for incoming light energy. In light-adapted sample some of the reaction centers are saturated with the ambient light and therefore cannot accept all photons of the incoming light and you get lower QY value. You could of course compare QY values of light-adapted samples, but the result could be affected by light conditions before the measurement.
  • How long dark-adaptation time is recommended?
  • Duration of dark adaptation depends on species, in general it is between 5 and 15 minutes.
  • Do the Ft values change within one measurement or between measurements? Should I do some kind of calibration or programming before measuring?
  • The value can change slightly (in range 10%). If the change within one measurement is bigger, it is recommended to set the f_pulse intensity lower. Strongly increasing Ft value within one measurement means, that f_pulse is too strong and causes unwanted "actinic effect" (= photochemistry starts). Fluorescence measurements do not require calibration.
  • Can you explain meaning of the 'f_pulse' in the AquaPen device?
  • This function serves for setting of measuring pulses intensity. The measuring pulses are weak pulses, which are able to induce the minimal chlorophyll fluorescence (Fo or Ft). It takes only 30 µs and the maximum intensity is 3000 µmol photon.m^-2.s^-1. It means 30 µs * 3000 µmol photon.m^-2.s^-1 = 0,09 µmolphoton.m^-2 per pulse is the maximal intensity of the f_pulse.
  • Can you explain meaning of the 'F_pulse' in the AquaPen device?
  • This function serves for setting intensity of the saturating pulse. Saturating pulse is able to induce maximum chlorophyll fluorescence (Fm). 100% of intensity equals approximately 3000 µmol photon.m^-2.s^-1.
  • Can you explain meaning of the 'A_pulse' in the AquaPen device?
  • This function serves for setting intensity of measuring pulses. Actinic light is basically the ambient light in which the plants are growing. 100% of intensity equals approximately 1000 µmol photon.m^-2.s^-1.
  • In the AquaPen, Fv/Fm, Fv'/Fm' and qP from the OJIP test, I can easily have the Fv/Fm value. Then for the Fv'/Fm' (thus the light adapted quantum yield of PSII) which values should I use (is it calculated or not)? Also for the qP (proportion of open PSII, [Fm'-Ft/Fm'-Fo']) is there any value coming out from the tests or should I calculate it by myself (or from the NPQ test?)?
  • During OJIP curve measurement you do not use any light adaptation phase and therefore it is not possible to obtain PSII efficinecy in light adapted state and qP. OJIP is fast measurement of variable fluorescence transient during saturation pulse. To obtain Fv'/Fm' and qP you will need to use either Light Curve protocols or NPQ protocol.
  • We carried out several NPQ tests, but from the AquaPen datasheet I am not able to discriminate which is the NPQ value (Fom-Fm')/Fm'. Please could you explain to me a bit better what the data sheet from the NPQ means?
  • There are quite some explanations regarding each of the protocols available in the Fluorpen in the manual. For the NPQ you should refer to the page 35. You can find also description of the parametres measured and calculated. NPQ is calculated as (Fm – Fm_Ln) / Fm_Ln. You obtain NPQ value calculation for each of the Fm´value measured by saturation pulse during light and dark adapted state.
  • Should the Light Curve and OJIP protocols be done after a dark adaptation?
  • It is recommended to dark-adapt the samples before the chlorophyll fluorescence measurement. Duration of adaptation depends on the plant species, but in general 15 minutes should be sufficient. More information about the NPQ protocol can be found in the Operating Manual, page 32 – 36. Here are explained all parameters of this protocol. OJIP measurement reflect the chlorophyll fluorescence induction kinetics. O, J, I, and P steps correspond to the redox states of PS II and PS I and to the efficiencies of electron transfer through the intersystem chain to the end electron acceptors. If you want know the efficiency of the photosystem, you should better measure the Fv/Fm parameter.
  • In the AquaPen, I run few light curve tests (is the only one where I can see the Ft value): now, to calculate the ETR, I used the YII*PAR*0.84*0.5 equation (thus is giving me the response curve). Is that right? Thus, should I use the QY L value at each step (1-2-3 etc.) for each light intensity (i.e. for LC 2 is 0, 100, 200,300,500,1000 referring to QY max, QY L1, QY L2, QY L3 etc.)?
  • Exactly, the QY_Lss (YII) is calculated as (Fm_L – Ft_L) / Fm_L . ETR is calculated exactly as you wrote: YII*PAR*0.84*0.5.
  • Is it possible to measure only Chlorophyll A with the AquaPen-C?
  • The AquaPen measures Chlorophyll A and Chlorophyll B together. Excitation lights are 455 nm and 620 nm, emission band is 660-750 nm.
  • We received the AquaPen-C with a calibration certificate. Does it mean that the device is calibrated for both the optical density and chlorophyll content?
  • In our testing laboratory, each AquaPen-C is calibrated for approximate chlorophyll content in suspension. We use our internal quality standard in which the OJIP measuring protocol is applied. The calibration is performed both for blue light (testing is done with green alga Chlamydomonas reinhardtii) and for red light (used is marine cyanobacterium Cyanothece). We do not perform optical density calibration since our customers prefer doing their own calibration on the specific organisms they are investigating.
  • In the AquaPen-C there is a function CAL. OD. How long it takes to execute once? For calibration, should I put the cuvette in the slot, blank or filled with water?
  • If you want to measure the optical density, OD calibration should be performed after every swich ON of the device, because the previous calibration is not saved in the device memory. To get the most accurate results, we recommend to do calibration with the same cuvette using the same orientation which will be used for measurement. Calibration should be performed with distilled water or with cultivation medium. To check if calibration was done well, measure OD680 and OD720 of the calibration liquid (distilled water or medium). The result should be max 0,0003. If it is higher, perform the calibration again.
  • How should I adjust the measurement when I get „over-flow“ error message during ChlF measurement in the AquaPen?
  • The „over-flow“ error message means that the ChlF signal is above the range of detection. The sample is too concentrated and should be diluted. As an example: For standard type of culture such as Chlorella vulgaris with OD 680 of 0.1 and AquaPen pulse setting of f_pulse 30%, F_pulse 70% the ChlF measurement can be measured correctly without any overflow error warning.
  • How should I adjust correctly the f-pulse (measuring flashes) settings prior to measurement with the AquaPen?
  • The optimum value of f_pulse can be identified for instance with the QY measurement. Before initiating the QY measurement it is recommended to set the pulse color based on the type of measured culture (Algae or cyanobacteria) and intensity of F_pulse on 70%. QY measurement should be performed with dark adapted culture. If you use the cuvette version of the AquaPen, make sure that you use always fresh 4 ml of culture for each individual measurement (culture can be inhibited after measurement) or you wait given period of time between the individual measurements (to ensure relaxation of photosynthetic apparatus during the dark adaptation of the sample prior next measurement). The f_pulse setting recommended by the manufacturer is 30%. You can increase the intensity of f_pulse in case your culture has very low density. Please note that high intensities of f_pulse can cause undesirable “actinic effect” resulting in increase of F0 value - in this case F0 isn´t real dark adapted F0 and QY value will be lower. The f_pulse intensity at which the highest value of QY is reached is the optimal one for your culture.
  • How should I adjust correctly the F-pulse (saturation pulse) settings prior to measurement with the AquaPen?
  • The best way to recognize the optimum intensity of F_pulse is to perform OJIP measurement. During OJIP measurement solely F_pulse (saturating pulse) is used for ChlF measurement. OJIP measurement should be performed with dark adapted culture. If you use the cuvette version of the AquaPen, make sure that you use always fresh 4 ml of culture each individual measurement (culture can be inhibited after measurement) or you wait given period of time between the individual measurements (to ensure relaxation of photosynthetic apparatus during the dark adaptation of the sample prior next measurement). The F_pulse setting recommended by manufacturer is 70%. The F_pulse intensity at which the highest value of Fv/Fm is reached is the optimal one for your culture.
  • Can I measure chlorophyll concentration in the AquaPen-C, and at which range?
  • In the AquaPen-C, chlorophyll concentration is based on optical density measurements at 680 nm. Minimal chlorophyll concentration which you can measure with this device corresponds to 0.5 µg chlorophyll/L. The upper limit is defined by the principle of OD measurement and the fact that values over OD 680 nm are influenced by large error of measurement.
  • How big is the memory in AquaPen device? How many OJIP curves can be saved in the device internal memory?
  • About 1100 OJIP curves can be saved at one time.
  • How is defined optical density in the AquaPen-C?
  • It is defined as OD = -Log(I/Io) where Io is the irradiance that is transmitted through the cuvette filled with medium without algae or other organisms. This quantity must be measured as the reference. I is the irradiance transmitted through the cuvette with algal or cyanobacterial suspension in which OD is measured. Log is the decadic logarithm of the I/Io ratio. Thus, optical density OD = 1 means that light at the respective wavelength is attenuated by algae or cyanos 10 times relative to the reference. With OD = 2, the attenuation relative to the reference is 100 times.
Monitoring Pen
  • What is measuring time of the Monitoring Pen protocols?
  • It differs for single protocols: Ft takes about 100 ms, OJIP and QY about 1-2 seconds, NPQ and LC protocols take up to few minutes.
  • In which units is measured fluorescence in Monitoring Pen devices?
  • Fluorescence is measured in relative fluorescence units, also called arbitrary units (A.U.).
  • I have a problem downloading data from our Monitoring Pen. When the device gets to the end (100%) of the download, it gives an Error: TFpData:parse Data0 -> unknown ID 0. And then just sits with the spinning circle and there is no way to get data off the unit.
  • This error means that the data in internal memory are corrupted. The reason for that could be for example power failure (battery dead or removed) during data saving procedure. If there are no important data it could be easily solved by erasing the memory.
  • Can I measure Ft and QY in presence of light (without dark condition)?
  • Basically all measured fluorescence parametres can be acquired either after dark adaptation or in the light adapted state. Ft refers to Fo if the leaf sample is dark-adapted (Fo refers to minimal level of fluorescence in dark adapted state). QY measured in the light is equal to Fv´/Fm´ and it provides an estimate of the PSII maximum efficiency within light-adapted material in contrast to Fv/Fm which is an estimate of the PSII maximum efficiency within dark-adapted material. Explanation of particular parameters: Fo - minimum fluorescence signal (when all PSII centres are in the open state) from dark-adapted material; Fo' - minimum fluorescence signal (when all PSII centres are in the open state) from light-adapted material; Ft - fluorescence signal at any point between Fo' and Fm', in other words instaneous fluorescence which is affected by the level of light the object is exposed to; Fm - maximum fluorescence signal (when all PSII centres are in the closed state) from dark-adapted material; Fm' - maximum fluorescence signal (when all PSII centres are in the closed state) from light-adapted material.
  • Is it good to measure dark-adapted samples?
  • It is recommended to measure dark-adapted samples. The dark-adaptation guarantees the same starting conditions before measurement of samples cultivated in different conditions. But what is more important you get better results (= higher photosynthetic performance), because in dark all reactions centers of PSII relax and are ready for incoming light energy. In light-adapted sample some of the reaction centers are saturated with the ambient light and therefore cannot accept all photons of the incoming light and you get lower QY value. You could of course compare QY values of light-adapted samples, but the result could be affected by light conditions before the measurement.
  • How long dark-adaptation time is recommended?
  • Duration of dark adaptation depends on species, in general it is between 5 and 15 minutes.
  • Do the Ft values change within one measurement or between measurements? Should I do some kind of calibration or programming before measuring?
  • The value can change slightly (in range 10%). If the change within one measurement is bigger, it is recommended to set the f_pulse intensity lower. Strongly increasing Ft value within one measurement means, that f_pulse is too strong and causes unwanted "actinic effect" (= photochemistry starts). Fluorescence measurements do not require calibration.
  • Can you explain meaning of the 'f_pulse' in the Monitoring Pen device?
  • This function serves for setting of measuring pulses intensity. The measuring pulses are weak pulses, which are able to induce the minimal chlorophyll fluorescence (Fo or Ft). It takes only 30 µs and the maximum intensity is 3000 µmol photon.m^-2.s^-1. It means 30 µs * 3000 µmol photon.m^-2.s^-1 = 0,09 µmolphoton.m^-2 per pulse is the maximal intensity of the f_pulse.
  • Can you explain meaning of the 'F_pulse' in the Monitoring Pen device?
  • This function serves for setting intensity of the saturating pulse. Saturating pulse is able to induce maximum chlorophyll fluorescence (Fm). 100% of intensity equals approximately 3000 µmol photon.m^-2.s^-1.
  • Can you explain meaning of the 'A_pulse' in the Monitoring Pen device?
  • This function serves for setting intensity of measuring pulses. Actinic light is basically the ambient light in which the plants are growing. 100% of intensity equals approximately 1000 µmol photon.m^-2.s^-1.
  • In the Monitoring Pen, Fv/Fm, Fv'/Fm' and qP from the OJIP test, I can easily have the Fv/Fm value. Then for the Fv'/Fm' (thus the light adapted quantum yield of PSII) which values should I use (is it calculated or not)? Also for the qP (proportion of open PSII, [Fm'-Ft/Fm'-Fo']) is there any value coming out from the tests or should I calculate it by myself (or from the NPQ test?)?
  • During OJIP curve measurement you do not use any light adaptation phase and therefore it is not possible to obtain PSII efficinecy in light adapted state and qP. OJIP is fast measurement of variable fluorescence transient during saturation pulse. To obtain Fv'/Fm' and qP you will need to use either Light Curve protocols or NPQ protocol.
  • We carried out several NPQ tests, but from the Monitoring Pen datasheet I am not able to discriminate which is the NPQ value (Fom-Fm')/Fm'. Please could you explain to me a bit better what the data sheet from the NPQ means?
  • There are quite some explanations regarding each of the protocols available in the Fluorpen in the manual. For the NPQ you should refer to the page 35. You can find also description of the parametres measured and calculated. NPQ is calculated as (Fm – Fm_Ln) / Fm_Ln. You obtain NPQ value calculation for each of the Fm´value measured by saturation pulse during light and dark adapted state.
  • Should the Light Curve and OJIP protocols be done after a dark adaptation?
  • It is recommended to dark-adapt the samples before the chlorophyll fluorescence measurement. Duration of adaptation depends on the plant species, but in general 15 minutes should be sufficient. More information about the NPQ protocol can be found in the Operating Manual, page 32 – 36. Here are explained all parameters of this protocol. OJIP measurement reflect the chlorophyll fluorescence induction kinetics. O, J, I, and P steps correspond to the redox states of PS II and PS I and to the efficiencies of electron transfer through the intersystem chain to the end electron acceptors. If you want know the efficiency of the photosystem, you should better measure the Fv/Fm parameter.
  • In the Monitoring Pen, I run few light curve tests (is the only one where I can see the Ft value): now, to calculate the ETR, I used the YII*PAR*0.84*0.5 equation (thus is giving me the response curve). Is that right? Thus, should I use the QY L value at each step (1-2-3 etc.) for each light intensity (i.e. for LC 2 is 0, 100, 200,300,500,1000 referring to QY max, QY L1, QY L2, QY L3 etc.)?
  • Exactly, the QY_Lss (YII) is calculated as (Fm_L – Ft_L) / Fm_L . ETR is calculated exactly as you wrote: YII*PAR*0.84*0.5.
  • How big is the memory in Monitoring Pen devices? How many OJIP curves can be saved in the device internal memory?
  • About 1100 OJIP curves can be saved at one time.
PlantPen
  • Is there correlation or conversion between SPAD and NDVI index that is measured in the PlantPen NDVI-310?
  • There is strong correlation between SPAD and NDVI index, yet no direct conversion is possible. But both measurements refer to the same physiological information about the plants.
  • What is expected number range for PRI measurements in the PlantPen device?
  • The range of PRI is -1 to +1.
  • What is meaning of functions: Multiplication and Average in the PlantPen Setting Menu?
  • Multiplication is for obtaining the multiplied results. Multiplication could be x10, x100, x1000. It means, the result is PRI = 0.0523 when multiplication is set 1x, PRI = 0.523 when 10x, PRI = 5.23 when 100x and PRI = 52.3 when 1000x. Average measures the sample defined times (eg. 25x) and makes the average values from these 25 measurements. Higher the average value, then longer is the measuring time (but still it is couple of seconds). It could be useful for getting more precise results.
  • What is meaning of functions A and B, which appear in the measuring process in the PlantPen?
  • It means the reflectance values at 531 nm and 570 nm from which the PRI parameter is calculated (PRI = (R531-R570)/(R531+570)), A = R531 nm; B = R570.
  • Can I obtain trustworthy results when measuring with PolyPen RP 410 or PlantPen if my plant samples are small, smaller than the optical entrance of these devices?
  • Yes it is possible to measure smaller leaves with minor limitation. The leaf clip is equipped with white coating that is used for calibration. When you use smaller leaves the white coating become "visible" for the instrument and influence the results. This can be fixed by putting some black material as a background for the leaf to cover white coating during measurement.
N-Pen
  • Are nitrogen values measured and displayed in % in N-PenN 110 given in absolute or relative values?
  • N-Pen measures nitrogen content in plant dry matter (in %) and predicts protein content in grains (in %). The measurements are precise if second youngest leaves are measured at mid-tillering.
  • I understand that the N-PenN 110 device does not provide formulas of relative nutrition state for each growth stage and corresponding nitrogen nutrition recommendations. But can you at least provide with a prediction of nutrition state?
  • Yes,simplified predictions are: (1) Green NDVI higher than 0.65 indicates 100% nitrogen nutrition state (N=100%); (2) Green NDVI lower than 0.25 indicates 0 % nitrogen (N=0%); (3) If Green NDVI value is in between 0.25 and 0.65, then nutrition state is calculated as N (%) = (green NDVI – 0.25) * 250. The nutrition state in younger plants during tillering should be generally higher than in later stages with emerged flag leaf.
  • Can N-PenN 110 be calibrated to measure nitrogen values in other plants than barley, wheat and maize?
  • Theoretically, the N-Pen can be calibrated for any plant species. In N-Pen leaf reflectance is correlated with nitrogen content that is determined by chemical analysis. Calibration procedure must include measuring optical signal with the N-Pen and analysis of chemically measured leaves for N content (standard AAS). Enough repetition is needed for statistical analysis; finding appropriate time and conditions for measurements during the plant growing season is also important.
PolyPen RP 410
  • In the PolyPen RP 410, besides the different indices we get different Excel spreadsheets with: Spectrum / Spectrum Scope / Spectrum Absorbance / Spectrum Transmittance. But no reflectance?
  • Export options in the software are related to calculation not the physical measurement setup. We are using the same software for multiple SpectraPen versions and thus not all options may be active in the PolyPen. Here are short descriptions of the export options: Spectrum - raw data with separate dark and reference spectra; Scope - scope data with dark subtraction (not in PolyPen); Transmitance - transmitance = I/Iref; Absorbance - absorbance = log Iref/I. Reflectance is calculated the same way as transmittance (it is not measured through a leaf).
  • Can we measure transmittance and absorbance with the PolyPen RP 410?
  • Polypen is measuring reflectance. Transmittance/absorbance may be calculated according to this formula: T=I/I0 or A = log I0/I.
  • How transmittance is calculated in the PolyPen RP 410?
  • Transmittance is calculated from reflectance as T = I/I0, where T = transmittance, I = measured light intensity, I0 = reference light intensity, basically it is the reflectance corrected to white calibration standard. White calibration is done by inserting the Spectralon under the leaf clip.
  • Is the reflectance standard used in the PolyPen RP 410 calibrated?
  • No, it is not calibrated but the error is less then 2%.
  • How can I clean the reflectance standard used in the PolyPen RP 410?
  • Please see the video or check instructions.
  • How can we synchronize PolyPen RP 410 and GPS measurements made in field?
  • GPS logger is tracking the position automaticaly every 1 second, you dont have to do anything. The data and position is then synchronized according time in the PC software. Time must be properly set in both devices.
  • What is the maximum reading number we can measure with PolyPen RP 410?
  • Maximum raw value is 65535. The sensitivity is set automaticaly during calibration so you don’t have to worry about it.
  • What is lifetime of the LED used in the PolyPen RP 410?
  • LED lifetime depends on the frequency of usage. Under normal conditions it exceeds 5 years.
  • Can I obtain trustworthy results when measuring with PolyPen RP 410 or PlantPen if my plant samples are small, smaller than the optical entrance of these devices?
  • Yes it is possible to measure smaller leaves with minor limitation. The leaf clip is equipped with white coating that is used for calibration. When you use smaller leaves the white coating become "visible" for the instrument and influence the results. This can be fixed by putting some black material as a background for the leaf to cover white coating during measurement.
  • How can I program my own index in the PolyPen RP 410?
  • If you want to calculate your own index, you can of course do it from the raw data in Excel or you can add this formula to the Config/Formulas.txt in the PolyPen program folder. Syntax is very simple, for example: Transmitance:CRI2:Caroteniod Reflectance Index 2:1/Transmitance[510nm]-1/Transmitance[700nm]. Each parameter is separated with colon: the first one is data set which will be used as source data (leave there Transmitance); the second is name; the third is description and the last one is calculated formula. After you edit the Formulas file, restart the SpectraPen software. Your index should appear in the list and also in the exported data.
  • Does the PolyPen RP 410 work also on monocot leaves with a prominent midvein?
  • The PolyPen should work as well on monocot species, basically with the similar principle as the NDVI and PRI PlantPens are working. These devices have been tested and used for monocot species. However it is important to remember that veins can indeed cause some interferences during the measurement and that the first leaves of same age should be cross-compared and, in an ideal case, the method should be standardized to the same part of the leaf.
  • What is difference in use between the white and black leaf clips in the PolyPen RP 410?
  • Black leaf clip is limiting the measurement to reflectance only and it is preferable. White leaf clip is for transmittance measurement (actually it is a combination of reflectance and transmittance). It could be useful for some application.
  • Can you shortly explain the difference in between the PolyPen RP 410, SpectraPen SP 110 and SpectraPen LM 510 ?
  • PolyPen RP 410 measures reflectance on leaves or other plant samples. It is capable of calculation of various reflectance indices (some of them are pre-programmed). It features an integrated light source and a leaf clip. SpectraPen SP 110 is a spectrometer without spectroradiometric calibration. It features a SMA905 light fiber port. It is intended for measuring reflectance, transmitance and light wavelength. SpectraPen LM 510 is a spectroradiometrically calibrated spectrometer with integrated cosine corrector. It measures absolute values of light intensity in uW/cm2/nm and photon flux density in umol/m2/s/nm. It calculates: irradiance (uW/cm2/), PAR (umol/m2/s), illuminance (Lux), CIE1931 coordinates, CCT (L).
SpectraPen SP 110
  • Can you explain function of cosine corrector in SpectraPen SP 110?
  • Standard SP 110 has a connector for attaching light fiber (SMA905). If you don’t attach anything on this connector, there is a small angle in which light is accepted by the instrument (what the instrument sees) - it is about 30 degrees. Cosine corrector is used for collecting light from 180 degrees angle. It is used for relative and absolute spectral intensity measurements, for emissive color applications, and for evaluation of light sources such as LEDs and lasers. Usage is optional and the corrector can be connected or disconnected very easily.
  • Can you shortly explain the difference in between the PolyPen RP 410, SpectraPen SP 110 and SpectraPen LM 510 ?
  • PolyPen RP 410 measures reflectance on leaves or other plant samples. It is capable of calculation of various reflectance indices (some of them are pre-programmed). It features an integrated light source and a leaf clip. SpectraPen SP 110 is a spectrometer without spectroradiometric calibration. It features a SMA905 light fiber port. It is intended for measuring reflectance, transmitance and light wavelength. SpectraPen LM 510 is a spectroradiometrically calibrated spectrometer with integrated cosine corrector. It measures absolute values of light intensity in uW/cm2/nm and photon flux density in umol/m2/s/nm. It calculates: irradiance (uW/cm2/), PAR (umol/m2/s), illuminance (Lux), CIE1931 coordinates, CCT (L).
SpectraPen LM 510
  • What is maximum light intensity that can be measured by the SpectraPen LM 510 light meter?
  • Intensity up to 5,000 umol/m2/s can be measured.
  • Does the SpectraPen LM 510 use a CCD-chip or Prisms monochromator?
  • It uses a Polychromator with CMOS linear image sensor.
  • In SpectraPen LM 510 , what is the average light sensitivity per channel?
  • The integration time of the sensor is automatically adjusted between 5ms up to 10s to accurately measure the light intensity between 1 umol m−2s−1 up to approx. 5000 umol m−2s−1.
  • Can SpectraPen LM 510 measure the intensity of light individually for pre-selected parts of spectrum?
  • Yes, one pre-selected part of spectrum can be measured at one time.
  • Can you shortly explain the difference in between the PolyPen RP 400, SpectraPen SP 100 and SpectraPen LM 500?
  • PolyPen RP 400 measures reflectance on leaves or other plant samples. It is capable of calculation of various reflectance indices (some of them are pre-programmed). It features an integrated light source and a leaf clip. SpectraPen SP 100 is a spectrometer without spectroradiometric calibration. It features a SMA905 light fiber port. It is intended for measuring reflectance, transmitance and light wavelength. SpectraPen LM 500 is a spectroradiometrically calibrated spectrometer with integrated cosine corrector. It measures absolute values of light intensity in uW/cm2/nm and photon flux density in umol/m2/s/nm. It calculates: irradiance (uW/cm2/), PAR (umol/m2/s), illuminance (Lux), CIE1931 coordinates, CCT (L).
LaiPen
  • What is the difference in between the LAI-2000 and LaiPen LP 110?
  • LAI-2000 measures the attenuation of diffuse sky radiation at five zenith angles simultaneously, it has five detectors. The correct way of measurement is conditioned by attaching an appropriate view cup to hide foreign objects in the field of view. Our LaiPen is designed to avoid the system of view restrictor cups. This means it has a single view cup and a single detector and the four subsequent angles must be measured separately with the help of build-in electronic inclinometer and visual-acoustic indicator. In LaiPen, the permanent restricting cup has restriction angle 160 along x axis and 1120 along y axis, which is different from LICOR LAI 2000.
  • Can I correct measurements for clumping effects in the LaiPen LP 110?
  • The only measurement you do with LaiPen is irradiance. In this respect, you can not correct measured irradiance values for clumping during measurement, but you can correct your calculation of LAI index afer you download irradiance values from LaiPen to computer.
  • What is the exact geometry/configuration of the ring sensors in the LaiPen LP 110?
  • There are no ring sensors in LaiPen. Instead, the LaiPen device is equipped with a single wide-angle optical sensor used in conjunction with a cup restricting 160 / 1120 angle sector. All angles (in multiple angle measurement mode) are measured only with one sensor. The other four angles are obtained by subsequent inclinations of the device from zenith angle, which is controlled by electronic inclinometer with pre-defined five angle positions.
  • Can I exclude specific rings from the LaiPen LP 110 computation, or change path lengths of different rings (not homogeneous canopy) or measure single trees?
  • In multiple-angle measurement mode you always measure all five angles. But since the data you download from the LaiPen to computer for further processing are only uncomputed raw values, exclusion of any measurement would be possible. It is not possible to change the path lengths - these are fixed. And the single trees measurement, for sure it can be done.
  • The website claims we can measure under different sky conditions with the LaiPen LP 110, but the way the instrument deals with this is unclear?
  • The dual sensor mode of measurement alows to estimate reference values for each particular time of measurement in changing weather conditions much more efficiently than the single sensor mode. The way how single sensor mode of measurement deals with this issue is decribed in the first version of Lai Pen manual (chapter 7.A. Single Sensor Mode of Measurement). The computation in case of dual sensor mode of measurement is described in the second attached file named: “Dual mode_ Introduction.pdf”, which is not included in the first version of manual.