Honeywell HERMetic UTImeter Gtex Chem IIC, Operation And Service Manual, Page: 17 / 83

50489/GTEX Chem IIC/1805 UTImeter Gtex Chem IIC
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6.2.3. Interface detection
The principle consists of a conductivity
measurement between an active
electrode and a grounded electrode.
When the liquid is conductive (as water),
the ullage sensor detects the presence of
the liquid as well and the conductivity
electrodes and associated electronic
circuits modulate the coded signal to
generate the intermittent beep.
1
6
0
1
2
3
4
5
0
1
1
2
1
Interface level
Interface sensor
4 mm
Water
Oil
Air
Oil
Figure 7-4
The reaction point is located 4 mm (5/32") from the sensor bottom and identical with the zero-point of the tape graduation.
6.2.4. Temperature measurement
The sensing element is a Platinum Resistance
Temperature Detector (RTD) element. The
element is located in the temperature electrode,
which is filled in with a heat transfer compound
paste to reduce the response time.
The RTD element signal is digitized, and then all
errors (offset, non-linearity and drift) are corrected
and compensated by the micro-controller located
in the sensor probe. The RTD element
characteristics are stored in the sensor memory
and are dedicated to one sensor. For this reason,
changing a sensor does not require a new
calibration.
All data are serialised and sent by the micro-
controller to the Display Unit.
Temperature settings (resolution, scale) are easy
to select by pressing the 5-key control panel.
1
6
0
1
2
3
4
5
0
1
1
2
1
Temperature level
Temperature sensor
4 mm
Liquid
Air
Figure 7-5
The reaction point is located 4 mm (5/32") from the sensor bottom and identical with the zero-point of the tape graduation.