SRH400 Operating Instructions
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8.3 1-point RH and T adjustment
For best performance, the RH and the T adjustment point
shall be selected at the middle of the RH and T measurement
range of main interest.
1. Set the jumper to RH calib or to T Calib.
2. Place the probe into the corresponding calibrator and let
it stabilize at the selected RH or T value for at least 30
minutes.
3. For adjustment point in the lower half of the output scale,
press and hold S2 for 3 seconds. The LED “Calib” will light
and the symbol “CAL<” will appear on the SRH400 display.
For adjustment point in the upper half of the output scale,
press and hold S1 for 3 seconds. The LED “Calib” will light
and the symbol “CAL>” will appear on the SRH400 display.
4. Push S1 (up) or S2 (down) to bring the measured value in
line with the reference in steps of 0.1. The actual corrected
value is indicated on the display and can be measured at
the analogue output.
5. Press and hold S1 for 3 seconds to store adjusted value
in the S07 probe and end the first (low) point adjustment.
The LED “Calib” will be deactivated and the display will
show “CAL”.
Alternative: Press and hold S2 for 3 seconds to exit the
adjustment mode without storing the adjustment data.
The LED “Calib” will deactivate and the symbol “CAL”
disappears from the LC display.
8.4 Return to factory calibration
During normal measurement mode of SRH400 (NOT during
adjustment mode!) press and hold together S1 and S2 for 5
seconds. The return to factory calibration is indicated by one
flash of the LED “Calib”.
8.5 Loop adjustment and calibration in the field
Loop calibration or adjustment in the field, as required by the
FDA (Food and Drugs Administration) regulated industries,
is easily possible for the SRH400 with two separate probes.
Use extension cables to drop the probes into calibrators
without dismounting or disconnecting the SRH400 basic
unit. The illustration shows the RH probe placed into the
Humor 20 high end portable humidity calibrator, and the T
probe in a dry block calibrator.
8.6 Probe individual adjustment
The probes can be adjusted individually with the optional
Product Configuration Adapter and the optional Product
Configuration Software.
9.0 Functional and accuracy check of
SRH400 basic unit
The SRH400 basic unit can be checked with respect to
functionality and accuracy by using the SRH400 Reference
Probes Set, order number SRH400XXX (Fig. 4).
The set consists of two reference probes, which supply each
a pair of fix humidity and temperature values as follows:
RH = 10 % , T = 45 °C (113 °F)
RH = 90 % , T = 5 °C (41 °F)
The set includes a test report for each reference probe.
For SRH400 basic unit dedicated for only one combined RH
& T probe, both RH and T check shall be performed with each
reference probe connected at the single probe connection
socket.
For SRH400 basic unit ordered with for two separate RH and
T probes, the RH check shall be done with each reference
probe connected to the first (left) socket, and then the T
check with the same probe connected to the second (right)
socket.
Humidity calibrator
Temperature
calibrator
RH probe
T probe
Figure 3.
Loop calibration
