IMT Analytics CITREX H3, User Manual

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23
Calibration
7
IMT Analytics AG
The various calibration options with CITREX H3 are described in this section. To avoid
incorrect measurements you must adhere to the procedures described here.
This adjustment is necessary if indication of the channel pressure sensor (P
channel
) or
a flow through open connection ports shows a value greater or less than zero. This
can occur if there are considerable temperature fluctuations, or after the warming-up
time. Zero calibration resets all values to zero. To perform zero calibration you must
remove all connected tubes from the device. Press the

icon and keep it pressed
for approx. 3 seconds. The screen shows a message "Zero Offset – Calibrating,
please wait".
Figure 19: Zero calibration
When you have switched on the device, individual displays may devi-
ate slightly from the zero point until operating temperature has been
reached. Zero calibration should never be performed with the device
cold. Warming-up time is approx. 10 minutes.
During zero calibration there must be no pressure being applied to a
connection port, and care must be taken to ensure that there is no
flow through the flow channel.
There are two different methods of calibrating the oxygen cell. The variant in which
the oxygen cell is calibrated with air only takes about two minutes. The second var-
iant consists of calibrating the oxygen cell with air and 100% oxygen. This so-called
two-point calibration adjusts the oxygen sensor more accurately and takes about
four minutes. Calibration can be selected by pressing the

button more than once.
7 Calibration
7.1 Zero point
7.2 Oxygen (O
2
) calibration