Z11.0.0X.6C-21
Operating manual
GGO -, GGA -, GOO -, GOG -
page 6 of 8
3. Application of the different sensor types
3.1. GGO housing (closed sensor)
For measurements at atmosphere and in systems without
over or under pressure the GGO... is sufficient. Additionally
the GGO can be screwed tightly into systems with small
over or under pressure. Attention! Mind the maximum pres-
sure and the maximum pressure difference at the mem-
brane.
GMH 3690: Always calibrate and measure at the same pressure!
GMH 3691: If pressure during calibration and measuring differs, please enter its value manually.
GMH 3692/3695: if instrument and sensor pressure are identical, it will be compensated
automatically.
3.2. GOO housing (open sensor)
The sensor is equipped with drillings at the end and be-
cause of its special construction the measuring gas
streams optimally around the sensor. No pressure can
appear while gas blows to the sensor, which otherwise
would result in erroneous measures. The temperature
compensation speed of the sensor also is optimised by
this design.
Especially the measuring of gases from compressed gas bottles
, where the expansion of the
gas leaving the bottle lowers the temperature, is optimised with regard to the temperature compen-
sation and pressure errors. The gas flow should be chosen in a suitable range, where no overpres-
sure can happen, esp. if the sensor is connected directly to the source e.g. by means of a tube.
3.3. GGA housing (closed sensor with pressure connection)
If You use an instrument with pressure connection
(e.g. GMH 3695), this type is optimal. Especially at
systems with over or under pressure
or at dy-
namic pressure due to gas flow. It can be screwed
tightly into systems with small over or under pres-
sure. Attention! Mind the maximum pressure. The
instrument pressure port is connected directly to the
sensor port. Then the actual pressure at the membrane will be measured and compensated auto-
matically.
3.4. GOG housing (ResOx Measuring)
The GOG / ResOx housings are specialized gas
sampling devices, which are suitable to sample
and analyse small gasprobes by means of a gas
sampling pump.
You get more informations in the referring GOG
und ResOx set manuals
4. Measuring Oxygen with the GMH 369x and GMH 569x
Calibration and measuring are depending of the absolute pressure at the sensor.
Therefore check the absolute pressure before calibration and measuring. When using a GMH 3691
(with manual pressure compensation) the pressure can be entered, when using a GMH 3690 the
pressure during calibration should be the same as during the measuring (otherwise e.g. 1% devia-
tion results in 1% measuring error).
The GMH 3692 /3695 /5690 / 5695 have integrated automatic pressure compensation. There you
only have to have in mind, that instrument and sensor membrane have the same pressure.
Sensor temperature and gas temperature should be the same.
Temperature differences may cause additional measuring errors! In worst case conditions it may
take up to several hours until both temperatures are adjusted. A suitable flow of the gas around the
sensor element increases the adjustment significantly.
