Apogee Instruments SQ-644-SS 소유자 매뉴얼 - 페이지 14

{카테고리_이름} Apogee Instruments SQ-644-SS에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apogee Instruments SQ-644-SS 16 페이지. Quantum light pollution sensor
Apogee Instruments SQ-644-SS에 대해서도 마찬가지입니다: 소유자 매뉴얼 (16 페이지)

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TROUBLESHOOTING AND CUSTOMER SUPPORT

Independent Verification of Functionality

Apogee SQ-644 Quantum Light Pollution Sensors provide a 4-20 mA output that is proportional to incident photon

flux density for the 340-1040 nm wavelength range. A quick and easy check of sensor functionality can be

determined using a DC power supply and an ammeter. Power the sensor with a DC voltage by connecting the

positive voltage signal to the red wire from the sensor and the negative (or common) to the black wire from the

sensor. Use the ammeter to measure across the white wire (signal output) and green wire (signal ground). Direct

the sensor head 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 4 mA.

Compatible Measurement Devices (Dataloggers/Controllers/Meters)

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SQ-644 Quantum Light Pollution Sensors are calibrated with a standard calibration factor of 12.5 µmol m

per

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mA, yielding a sensitivity of 0.08 mA per µmol m

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

controller) should have resolution of at least 0.08 mA in order to provide photon flux density resolution of 1 µmol

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and resolution of at least 0.008 mA in order provide photon flux density resolution of 0.1 µmol m

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

https://www.apogeeinstruments.com/downloads/#datalogger.

Cable Length

Shortening or splicing on additional cable in the field is generally not a problem for the current output of the SQ-

644. However, adding cable will result in a greater resistive load, which should be taken into consideration when

determining the maximum resistive load that the sensor will drive (see section above on Compatible Measurement

Devices). All Apogee sensors use shielded, twisted pair cable to minimize electromagnetic interference. For best

measurements, the shield wire must be connected to an earth ground. This is particularly important when using

the sensor with 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/).