Alpha Moisture Systems dewTEC DS2000, Инструкция по эксплуатации

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4.0 Hygrometer Settings
4.1 Sensor Calibration (AUTOCAL)
One of the most valuable advantages of the sensors is the Autocal feature.
The system relies on the fact that each sensor is designed to vice no further increase in reading
when it reaches its maximum moisture level. This means that the sensor will read its
maximum value when it is exposed to gas or air that is at that level and will continue to read
that value when it is exposed to wetter gas. The system can therefore be calibrated to the
analyser, on site, very simply by exposing the sensor to anything wetter than the maximum
level and adjusting the reading to the maximum dewpoint, on the hygrometer display, using
the Autocal Control on the hygrometer rear panel.
13 14 15 16 17 18 19 20 21
12 22
11 23
10 24
9 8 7 6 5 4 3 2 1
N/O
COM
N/C
+
-
TOP
N/O COM N/C
NPN
O/P1
COM NPN
O/P2
A COM B L N
Sensor
Connector
Autocal
Control
Factory calibration is performed by comparing readings given from the hygrometer with
readings obtained from a primary standard, traceable to The British Standard moisture
generator held at the National Physical Laboratory. These comparative readings are taken
after the sensor has been set to automatic calibration and the results are shown in the
calibration certificate supplied with each sensor.
To autocal the sensor, follow these simple steps:
1. Disconnect the coaxial cable from the sensor. Remove the sensor from its normal position
so it is exposed to ambient air or hold in the palm of the hand if the sensor full range is
+20ºC dewpoint.
2. Leave the sensor for approximately five minutes (this time is not critical but the
hygrometer reading should be stable before any adjustment is made. It is not advisable to
leave the sensor exposed to ambient air for more than a few minutes as this will impair
dry-down when the sensor is re-installed).
3. IF NECESSARY, adjust the Autocal control, on the analyser front panel, until the display
indicates the maximum level for the sensor range in use.
dewTEC DS2000 User’s Manual Page 13