Pentair HAFFMANS c-DGM, Instruction Manual

Page: 36 / 79

HAFFMANS c-DGM/i-DGM
Page 36 of 78 c-DGM/i-DGM
6.2.4.2 *O
2
continuous measurement in gas
With this measurement facility, the oxygen content is measured continuously while the gas to be
measured flows through the c-DGM. This setting is typically used when filling systems with CO
2
,
where for example the switching point from air to CO
2
must be found.
To carry out this measurement, the oxygen unit must be set for gas (see chapter 5.3). If this setting
is selected on one of these units, the solubility formula of oxygen is not applied, but the actual
proportion of oxygen in the gas is shown.
Also, the actual air pressure must be entered. Using this air pressure, a correction is applied to the
oxygen value to adjust for the air pressure at which the oxygen sensor is calibrated. The actual air
pressure can be set in the calibration menu (see chapter 7.2). There is no need to carry out an O
2
calibration.
The c-DGM can only measure gas when this is present atmospherically and with a slow flow. This
means that a flow meter must be connected to the instrument supply line. The maximum gas flow
which may be present at a c-DGM is 30 liters per hour.
Attention!
Use only low gas flows to flush the c-DGM. To pass compressed air,
calibration gases or gas to be measured through the c-DGM, use a
reducing valve; and set the flow to 30 liters per hour using a flow
meter.
A measurement is started as follows:
1. Extend the handle to the stop and set the lubrication valve fully open so that the gas can
flow out freely.
2. Press "Enter" for around 1 second.
The continuous oxygen measurement begins, and the current measurement
value appears on the display.
Depending on the setting of the O
2
sample time (see section 5.5.5), the
measured values are stored in the memory of the c-DGM.
A fully charged battery will allow around 8 hours of continuous oxygen
measurement.
3. The continuous oxygen measurement can be stopped by pressing "Enter" again or by
closing the handle.