Hydac HLB 1400 User Manual download pdf (Page 4)

Instruction Manual HYDACLab



03.03.2008

4. Functions

HYDACLab



sensors are compact, multi-functional sensors for determining the condition of fluids

online. Operators are kept informed of changes in fluid condition as they occur and can

immediately change the operating conditions accordingly.

Changes in fluid condition that might occur due to ageing or mixing with other fluids, for example,

are indicated by measuring temperature, relative humidity and relative changes in viscosity and

dielectric constant (also referred to as DC).

Those measurements are available as analogue signals and/or switching signals at the electrical

output of the HYDACLab



for activating warning devices or alarms.

For information on further readout possibilities (e.g. modular connection to a PLC control), please

see our website http://www.hydac.com

under “Downloads”, “Electronic”, or contact the appropriate

HYDAC agent.

4.1 Switching output (Standard Modification 000)

The NC switching output acts as a warning signal triggered by critical changes in the fluid

condition.

The switching output will switch whenever any of the following changes in measured values

occurs (the values stated are the standard factory settings):

Relative change in viscosity  10 % (temperature compensated)

Relative change in dielectric constant  15 % (temperature compensated)

Relative humidity  85 %

Temperature  80 °C

To activate the switching output the relative changes in viscosity and dielectric constant are

evaluated mathematically. It is therefore possible that the analogue values at the point of

switching will differ from the switching thresholds given above.

If, as a result of part-filling or re-filling the system, the values for the relative change in

viscosity return permanently to a window of  8 % or for the relative change in dielectric

constant to a window of  10 %, the switching output is deactivated again.

1 2 3 4 5 6 7 8 9 ... 17 18

No comments

Hydac HLB 1400 User Manual Page 4