Honeywell HERMetic UTImeter Gtex Chem - Interface Detection; Temperature Measurement

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7.2.3 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.
7.2.4 Temperature measurement
The sensing element is a Platinum Resistance Temperature
Detector (RTD) element. The element is located in the
temperature electrode, which is lled 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
Air
Oil
Water
Oil
4 mm
Interface sensor
Interface level
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.
1
6
0
1
2
3
4
5
0
1
1
2
1
Air
Liquid
4 mm
Temperature sensor
Temperature level
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.