Apogee Instruments SP-110 소유자 매뉴얼 - 페이지 18

{카테고리_이름} Apogee Instruments SP-110에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apogee Instruments SP-110 20 페이지. Pyranometer
Apogee Instruments SP-110에 대해서도 마찬가지입니다: 소유자 매뉴얼 (18 페이지)

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TROUBLESHOOTING AND CUSTOMER SUPPORT

Independent Verification of Functionality

Apogee models SP-110 and SP-230 pyranometers are self-powered devices and output a voltage signal

proportional to incident shortwave radiation. A quick and easy check of sensor functionality can be determined

using a voltmeter with millivolt (mV) resolution. Connect the positive lead wire from the voltmeter to the white

wire from the sensor and the negative (or common) lead wire from the voltmeter to the black wire from the

sensor. Direct the sensor diffuser toward a light source and verify the sensor provides a signal. Increase and

decrease the distance from the sensor head to the light source to verify that the signal changes proportionally

(decreasing signal with increasing distance and increasing signal with decreasing distance). Blocking all radiation

from the sensor should force the sensor signal to zero.

The heaters inside Apogee model SP-230 are designed to mitigate effects from snow, frost, and dew by warming

the sensor body temperature approximately 3 C above ambient air temperature, while under conditions of no

solar loading or radiant heating. A quick and easy check of heater functionality can be accomplished with an

ohmmeter. Connect the lead wires of the ohmmeter to the yellow and blue wires from the sensor. The resistance

should read approximately 780 Ω ± 1%.

Compatible Measurement Devices (Dataloggers/Controllers/Meters)

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Models SP-110 and SP-230 pyranometers are calibrated with a standard calibration factor of 5.0 W m

per mV,

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yielding a sensitivity of 0.2 mV per W m

. Thus, a compatible measurement device (e.g., datalogger or controller)

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should have resolution of at least 0.2 mV, in order to provide shortwave radiation resolution of 1 W m

An example datalogger program for Campbell Scientific dataloggers can be found on the Apogee webpage at

http://www.apogeeinstruments.com/content/Pyranometer-Unamplified.CR1.

Effect of Cable Length

When the sensor is connected to a measurement device with high input impedance, sensor output signals are not

changed by shortening the cable or splicing on additional cable in the field. Tests have shown that if the input

impedance of the measurements device is 1 mega-ohm or higher then there is negligible effect on the

pyranometer calibration, even after adding up to 100 m of cable. Apogee model SP series pyranometers use

shielded, twisted pair cable, which minimizes electromagnetic interference. This is particularly important for long

lead lengths in electromagnetically noisy environments.

Modifying Cable Length

See Apogee webpage for details on how to extend sensor cable length

(http://www.apogeeinstruments.com/how-to-make-a-weatherproof-cable-splice/).