Kipp&Zonen UVS-E-T UV Radiometers - Manual (Page 17)

6. Configuration Settings
6.1 Radiometer
In this page details about the radiometer must be entered.
6.1.1 Digital Instrument Calibration Certificates
The digital instrument calibration certificate (DCC) should have been delivered with your radiometer. The DCC holds the
relative radiometer response function and other radiometer calibration data. To use a DCC, import it by pressing
Import
Certificate. Importing makes a copy of the DCC file and puts it in the working directory. To remove a DCC, press Remove
Certificate. This will delete the DCC file from the current working directory. When your radiometer is re-calibrated, you should
import a new DCC. During processing of UV measurements, UVIATOR automatically uses the right DCC from the certificate list
based on calibration dates. In the output file(s) you will be warned when expired certificates have been used. A DCC can be
examined by double-clicking it in the certificate list.
6.1.2 View Correction Function
The correction function resulting from the atmosphere transmission model and a specific DCC can be examined and optionally
be stored to file by pressing
View Correction Function. You may lookup the value of the correction function for a specific solar
zenith angle and ozone column density by filling in their values at Graph Data Lookup.
The wavelength bandwidth (lambda) used for calculating the correction function, originates from the DCC. In case the atmosphere
transmission model does not cover the wavelength bandwidth of the DCC, the correction function cannot be calculated.
In order to make a comparison between corrected and uncorrected UV irradiance, the mean correction function is being calculated
and displayed in the correction function graph. It is represented as a transparent surface that has a constant value for all solar
zenith angles and ozone column densities. The mean correction function is the mean of all data points of the correction function.
The mean correction function is used to calculate
UV Irradiance (without correction).
6.1.3 Night-time Offset Correction
Enabling Night-time Offset Correction will instruct the program to calculate the radiometer offset voltage at night. The following
rules apply:
• The time used for offset calculation is localized by means of a correction based on longitude. This enables the program to
determine the most suitable time frame for calculating the radiometer offset voltage.
• The time frame for calculating the radiometer voltage is from 1 hour before till 1 hour after midnight localized time.
• The solar zenith angle (SZA) must be bigger than the configured
Minimum SZA for Offset Correction. The default value is 100 °,
which is 10 ° below horizon.
• The radiometer offset voltage will be calculated by averaging the radiometer voltages that meet the time frame and SZA rules.
The averaging weight of the radiometer offset voltage must be 3 or more.
When the calculated offset does not meet the rules above, the radiometer offset voltage as defined by the DCC will be used.
In order to monitor the radiometer offset voltage, enable the Offset column on the Output page.
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UVIATOR software manual