Description; General; Measuring Principle; Electrical Installation - ABS HSC2 Manual De Instrucciones

ABS
I
NSTALLATION AND USER MANUAL
1

Description

1.1

General

HSC2 is a microprocessor-based 2-wire loop-powered submersible hydrostatic
level sensor used to measure fluid levels. The HSC2 gives a 4–20 mA signal,
which is proportional to the level of the fluid. The output signal is connected to
the current-sensing mA input of e.g. set point relays, chart recorders, indicat-
ing instruments, PLCs, pump controllers etc.
The level sensor has a ceramic pressure sensor which can withstand very high
overpressures.
HSC2 can be adjusted, calibrated and tested with the calibration system CB2.
1.2

Measuring principle

The front side of the membrane senses the pressure of the liquid column, which
is proportional to the level of the liquid and the atmospheric pressure. Changes
in the atmospheric pressure affects the measurement and results in a
measurement error. To eliminate this error, the atmospheric pressure is
passed to the backside of the membrane through an air hose in the sensor
cable.
2

Electrical installation

+
9 – 60 VDC
–
+ –
HSC2
2.1

Overvoltage protection

When HSC2 is mounted in applications where there is a risk of overvoltage
(lightning), e.g. when long air cables are used, overvoltage protection should be
mounted.
2.2

Lengthening of the cable

When lengthening the cable, a shielded cable must be used. The connection
should be made with a joint box. If a cable without air hose is used for length-
ening, the joint box must have a small hole on the underside to allow pressure
equalisation.
HSC2, I
HYDROSTATIC LEVEL SENSOR
+ – + –
PLC, Setpoint relay etc.
NSTALLATION AND USER MANUAL
GB