Operation, 4 scaling – KROHNE OPTISENS PAS 2000 EN User Manual

Page 26

OPERATION

OPTISENS PAS 2000

www.krohne.com

11/2008 • MA PAS 2000 R04 en

5.3.2 Adjusting ORP

The ORP sensor is not re-calibrated, an offset adjustment is done instead. The offset adjustment
can be done in two ways: automatic or manual. Irrespective of the way you chose, you need a
buffer with a known potential.

Remove the sensor and, if necessary the electrode as well, but make sure that the electrode is
still connected to the signal amplifier. Wipe clean the electrode before adjustment. Now do the
steps that follow:

•

Spray the electrode using clean water, then immerse it in the first buffer, and wait for a stable

reading.

•

Enter the sensor menu. The output is frozen when the menu is opened.

•

Open the "Calibrate" menu, then select "Adjust", choose "Set" and press ^.

•

A window pops up asking for the ORP potential. Enter it and then press ^. MAC 080 will

calculate the difference and use it as offset.

5.4 Scaling

The Scale / Alarm

Scale / Alarm

Scale / Alarm menu (see the OPTISENS MAC 080 manual) allows the user to set the high and

low boundaries for a 4...20 mA output signal. In addition, this menu allows the user to set high
and low alarm values to switch a relay when solids have reached critical points.

Max

sets the 20 mA point output

Min

sets the 4 mA point output (may be negative for special applications)

Hi-Alarm

sets the high alarm set point; the value zero inactivates the alarm

Low-Alarm

sets the low alarm set point; the value zero inactivates the alarm

.book Page 26 Friday, November 28, 2008 2:32 PM