Honeywell HERMetic UTImeter Gtex Chem IIC, Operation And Service Manual, Page: 16 / 83

50489/GTEX Chem IIC/1805 UTImeter Gtex Chem IIC
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6.2. ULTRA sensing probe
6.2.1. Introduction
The ULTRA sensing probe consists of a
stainless steel tube terminated by a high-
tech plastic head which cannot be
removed from the tube. The sensing
probe includes an ultrasonic liquid level
sensor, a temperature sensor and a
conductivity electrode. The sensitivity for
ullage and interface measurement is not
adjustable. The temperature
measurement is calibrated at the factory
and does not require subsequent
adjustment.
6.2.2. Ullage detection
The ullage detector consists of two
piezoceramic plates and electronic
circuits. When the sensor head is
immersed in a non-conductive liquid (oil or
petroleum), the emitted ultrasonic signal is
detected by the receiver, coded and sent
to the instrument unit which activates the
buzzer with the continuous beep.
1
6
0
1
2
3
4
5
0
1
1
2
1
Reaction point
Ultrasonic level sensor
4 mm
Air
Liquid
Figure 7-3
The reaction point is located 4 mm (5/32") from the sensor bottom and identical with the zero-point of the tape graduation.