Apogee SU-100 Manual del usuario - Página 14

Navegue en línea o descargue pdf Manual del usuario para Accesorios Apogee SU-100. Apogee SU-100 16 páginas. Ultraviolet sensor

TROUBLESHOOTING AND CUSTOMER SUPPORT

Independent Verification of Functionality

Apogee SU-100 sensors are self-powered devices and output a voltage signal proportional to incident UV radiation. A quick

and easy check of sensor functionality can be determined using a voltmeter with millivolt resolution. Connect the positive

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

Direct the sensor head toward the sun and verify the sensor provides a signal. Blocking all UV radiation from the sensor

should force the sensor signal to zero.

Compatible Measurement Devices (Dataloggers/Controllers/Meters)

SU-100 UV sensors are calibrated with a standard calibration factor of 5.0 µmol m

per µmol m

. Thus, a compatible measurement device (e.g., datalogger or controller) should have resolution of at least 0.2

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mV in order to provide a measurement resolution of 1 µmol m

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

at http://www.apogeeinstruments.com/content/UV-Sensor.CR1.

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 greater than 1 mega-ohm there is negligible effect on the calibration, even after adding up to 100 m

of cable. 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.

Unit Conversion

SU-100 UV sensors are calibrated in photon flux units of µmol m

flux units of W m

. Example of this conversion can be found in the Knowledge Base of the Apogee website

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(http://www.apogeeinstruments.com/knowledge-base/; scroll down to UV Sensors section).

Modifying Cable Length

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

a-weatherproof-cable-splice/).

per mV, yielding a sensitivity of 0.2 mV

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. It is possible to convert the photon flux value to energy

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(http://www.apogeeinstruments.com/how-to-make-