COSA Xentaur Hygrocontrol Type 72 - Manual (Page 12)

Series 72 Manual page 8
Ensure that the calibration chamber faces downwards, to avoid direct contact of
the solution with the sensor. Before inserting the bottom into the chamber,
unscrew the chamber slightly, to help escaping air, when you close the
chamber. Tighten the chamber again after closing!
7. Program "CALIB"
7.1. Password Protection
To protect series 72 instruments against unwanted changes of their calibration,
this part of the program is protected by a password. You should give this
password only to trained and authorized personnel. The password has to be
calculated by a simple mathematical operation from the numeric last 4 digits of
the serial number of the transmitter. This is demonstrated by the following
example:
Let the serial number of the transmitter be: T23456
The first two digits of the password are formed by the sum of the digits number
3 and 4 of the serial number, the last two digits of the password are formed by
the sum of the last two digits of the serial number. In the above given example
of serial number we get:
3 + 4 = 07 for the first two digits,
5 + 6 = 11 for the last two digits.
The password in our example is then: 0711
7.2. Facilities of "CALIB"
The program "CALIB" holds all the facilities to:
a) recalibrate one or more points with menu "CHANGE"
b) add more calibrations with "CHANGE"
c) erase all humidity calibrations with "DELETE"
d) recalibrate temperature with "TEMPER"
e) enter a pressure factor, if measurement is done at a
constant, but not atmospheric pressure, with "PRESS"
f) return to measurement mode with "RUN"
g) return to beginning of "CALIB" with "RETURN"
To avoid any "uncertain" or "dubious” calibrations, the program uses two
principles, which are:
1) If one of the standard fixpoints is recalibrated, the former
value in memory is replaced.
2) If a nonstandard point is calibrated (for example a
saturated LiCl-solution), a standard fixpoint closer than
5% to the new calibration point will be replaced.
Two examples should illustrate this rules: