Kipp & Zonen PAR lite Instruction Manual Download Page 25 | Manualshive

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Kipp & Zonen PAR lite Instruction Manual Download Page 25

INSTALLATION AND MANTENANCE

Instruction manual PAR-LITE

22

4.3

Measuring modulated light

In the same way it is possible to shunt the PAR

LITE

with a

capacitor. This can be necessary when modulated light must
be measured. The PAR

LITE

has a response time much

smaller than 0,1s and much read-out equipment cannot
handle the resulting voltage pulses. At principle you must bring
the RC time above the period time of the lightpulses to get a
smooth signal. Due to the relative low impedance of the PAR

LITE

this need big capacitors. which can be problematic

because electrolytic capacitors are often useless due to their
battery effect. So use polyester, ceramic, etc types.

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Summary of Contents for PAR lite

Page 1: ...Instruction Manual Photosynthetic Active Radiometer PAR lite ...

Page 2: ...ng and maintenance instructions in the literature accompanying the instrument Should you have any comments on the product or this manual we will be pleased to receive them at Kipp Zonen B V Delftechpark 36 2628 XH Delft Holland P O Box 507 2600 AM Delft Holland Phone 31 0 15 2755210 Fax 31 0 15 2620351 Email info kippzonen com Web www kippzonen com Kipp Zonen reserve the right to make changes in t...

Page 3: ...ns can affect the validity of the CE declaration Kipp Zonen shall in no event be liable for incidental or consequential damages including without limitation lost profits loss of income loss of business opportunities loss of use and other related exposures however caused arising from the faulty and incorrect use of the product COPYRIGHT 2004 KIPP ZONEN All rights reserved No part of this publicatio...

Page 4: ...user guide 4 2 Sensor properties 7 2 1 Electrical 7 2 2 Spectral 9 2 3 Directional Cosine response 10 2 4 List of specifications 12 2 5 Dimensions 14 2 6 Expected output levels 15 3 Calibration 17 4 Installation and maintenance 19 4 1 Recalibration 20 4 2 Adjustment of calibration factor 20 ...

Page 5: ...CONTENTS Instruction manual PAR LITE 2 4 3 Measuring modulated light 21 5 Trouble shooting 23 6 Delivery 25 7 Accessories 27 ...

Page 6: ...CONTENTS Instruction manual PAR LITE 3 ...

Page 7: ...econd per square meter The PAR LITE is designed for continuous outdoor use Its calibration is valid for natural sunlight for artificial light it will be less accurate See the section on spectral sensor properties and calibration In its most frequent application the PAR sensor is used for agrometeorological and horti culture applications Typically it will be installed in a meteo mast and face upwar...

Page 8: ...GENERAL INFORMATION Instruction manual PAR LITE 5 can be done in the same way A levelling fixture is available as an option The PAR LITE fully complies CE with directive 89 336 EEC ...

Page 9: ... Darken the sensor The signal should read zero Expose the sensor to light The signal should give a positive reading Adjust the voltmeter range in such a way that the expected full scale output of the PAR LITE fits the full scale input of the voltmeter This can be done on theoretical considerations When the maximum expected radiation outdoors is 2 000 micro mol per second per square metre and the s...

Page 10: ... LITE body or through the holes in the optional levelling fixture The sensor should be mounted in a field which is free from obstructions Unless this is unavoidable no shadow should be cast upon it Maintenance the sensor should be kept clean using water or alcohol Recalibration is suggested every two years preferably by letting a higher standard run parallel to it during two different days a clear...

Page 11: ...characteristics fulfilling the so called cosine response 2 1 Electrical The electrical circuit of the PAR LITE is drawn in figure 1 The nominal output resistance of the PAR LITE is 240 Ω This implies that the input impedance of the readout equipment should be at least 30 kΩ in order to make an error of less than 1 percent Cable can be extended without problems to a length of 100 metres provided th...

Page 12: ...SENSOR PROPERTIES Instruction manual PAR LITE 9 Figure 1 Electrical circuit of the PAR LITE white ...

Page 13: ...AR LITE sensor and the ideal PAR spectral response together with the spectrum of the sun under a clear sky airmass 1 5 and the relative spectrum of a lamp with a colortemperature of 2856 K The sensor follows more or less the characteristic of a so called quantum response between 400 and 700 nm This is said to be the spectral area which is utilised by plants for photosynthesis For the photosynthesi...

Page 14: ...ity can differ from the sensitivity for daylight which is also determined by the individual bandwidth of the PAR LITE sensor Deviations can be of the order of magnitude of 5 Read also chapter 3 Calibration for this matter 2 3 Directional Cosine response The measurement of radiation received by a surface also called irradiance or radiative flux is laid down in two detector specifications that the d...

Page 15: ...hows the deviation from ideal behaviour expressed in percentage of the ideal value Figure 3 The directional response or cosine response of the PAR LITE On the horizontal axis the zenith angle On the vertical axis the percentage deviation from ideal cosine behaviour The curve can lift or fall for different azimuth or 2 5 at 70º zenith angle 6 4 2 0 2 4 6 0 20 40 60 80 Z EN IT H A N GLE degrees ...

Page 16: ...cted signal range under atmospheric conditions 0 12 mV Non stability within 2 year Non linearity within 1 up to 10000 µmol s m2 Temperature dependence of sensitivity within 0 2 C 0 1 typ Spectral Detector type Silicon photodiode plus filters Spectral range nominal 400 700 nm Cut on 50 400 15 nm Cut off 50 700 15 nm Quantumresponse match error 450 650 nm within 10 ...

Page 17: ... 80 angle of incidence within 10 azimuth error at 70 angle of incidence 5 pp Tilt response no error Mechanical Material of housing Anodized Aluminium Material of cable Poly Urethane Weight 110 g Cable length 3 metres Dimensions see figure 4 Environmental Operating temperature range 30 70 C Humidity 0 100 RH ...

Page 18: ...SENSOR PROPERTIES Instruction manual PAR LITE 15 2 5 Dimensions Figure 4 The dimensions of the PAR LITE in mm white lead positive green lead negative ...

Page 19: ...W m2 PAR sensor reading µmol s m2 µmol W s 10 Cloudless Typ 0 to 1300 Typ 0 to 2600 2 0 Cloudy Typ 0 to 500 Typ 0 to 1250 2 5 Table 1 Conversion from W m2 to µmol s m2 under cloudless and cloudy conditions The table serves as a rough cross check when also measuerments of the solar irradiance in W m2 are available ...

Page 20: ...nstruction manual PAR LITE 17 Cloud condition Pyranometer daily total W h m2 PAR sensor daily total mol m2 Cloudless Up to 11000 Up to 80 Cloudy Up to 4500 Up to 40 Table 2 expected daily totals the figures are indicative ...

Page 21: ... calibrated at the dutch standard laboratory NMI The resulting sensitivity is corrected to hemispherical solar radiation at airmass 1 5 The spectrum for airmass 1 5 was taken from the international standard ISO 9845 1 By this way we state that the PAR LITE sensitivity is most correct for hemispherical solar radiation with airmass 1 5 spectrum solar zenith angle 37 Under artificial light lamps of n...

Page 22: ...CALIBRATION Instruction manual PAR LITE 19 ...

Page 23: ...is such that no shadow is cast on the PAR LITE during any time of the day On the northern hemisphere this implies that the PAR LITE should be south of the mast The PAR LITE can be used to measure reflected radiation for instance when pointed towards the earth in the inverted position When measuring reflected radiation it is advised to measure at a height H of at least 1 5 meters above the surface ...

Page 24: ...4 2 Adjustment of calibration If necessary the sensitivity of the PAR LITE can be adapted This can be done by soldering a resistor between the white and green output wires In this way the internal resistance is shunted Suppose the internal load resistance Rl is 270 Ω To be sure measure the impedance of the PAR LITE with an Ohmmeter in the correct direction reverse voltage on photodiode Neglecting ...

Page 25: ...E has a response time much smaller than 0 1s and much read out equipment cannot handle the resulting voltage pulses At principle you must bring the RC time above the period time of the lightpulses to get a smooth signal Due to the relative low impedance of the PAR LITE this need big capacitors which can be problematic because electrolytic capacitors are often useless due to their battery effect So...

Page 26: ...INSTALLATION AND MANTENANCE Instruction manual PAR LITE 23 ...

Page 27: ...he circuit is blown With forward voltage across the photodiode you will mostly measure a resistance 240 Ohms if the photodiode circuit is OK If the PAR LITE shows bigger or smaller results than expected the following questions might help you out Are you measuring under natural sunlight If so the maximum expected radiation is 2600 µmol s m 2 Under lamps this might be sometimes more but often much l...

Page 28: ...NG Instruction manual PAR LITE 25 ohm If smaller than 3000 ohm you will notice errors of already 10 Is your readout equipment properly calibrated If still no satisfactory answer is found please contact your supplier ...

Page 29: ...DELIVERY Instruction manual PAR LITE 26 6 Delivery Delivery includes 1 PAR LITE sensor 0348900 1 calibration certificate 1 manual 0348200 ...

Page 30: ...DELIVERY Instruction manual PAR LITE 27 ...

Page 31: ...ACCESSORIES Instruction manual PAR LITE 28 7 Accessories CLF1 levelling fixture 0338700 ...

Page 32: ...n com Kipp Zonen USA Inc 125 Wilbur Place Bohemia NY 11716 United States of America T 1 0 631 589 2065 F 1 0 631 589 2068 kipp usa kippzonen com SALES OFFICES Go to www kippzonen com for your local distributor or contact your local sales office Our customer support remains at your disposal for any maintenance or repair calibration supplies and spares Für Servicearbeiten und Kalibrierung Verbrauchs...

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