HT-100F Series
HITROL CO., LTD.
8
Maintenance
The HT-100F Series level transmitter requires inspection for the sensor, drive, and transmission
sections. The sensor section has REED S/W; the drive section has the wire drum, spring drum,
and spur gear; and the transmission section has the R/I converter.
The service life of parts depends on the operation conditions, and regular inspection is
required to keep the optimum operation conditions. Thus, users are advised to conduct regular
inspection and maintenance at least every year. Exterior damages will be visually checked. The
R/I converter can be checked using a digital multimeter.
<Checking of the Sensor>
Disconnect the sensor wire from the H, C, and L terminals of the R/I converter, and
measure the resistance value of the sensor.
Low and Com
Resistance value of the current level
High and Com
Resistance value of the full level – Resistance value of the current level
High and Low
Resistance value of the full level
<Checking of the Drive>
1. Remove the front cover to see the gear operation.
2. Remove the rear cover to check the wire and measuring tape for any damage.
<Checking of the Transmission>
Check the output current of terminals T and – of the R/I converter using the digital multimeter.
※ The output current can be checked with the test points without opening its wire.
Sensor
Test Point
Indicator
R/I Converter
Power Supply
Digital Multimeter
After checking the sensor parts, the wrong connection of H, C, and L is the cause of the product failure.
