User Guide

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10 RELAYS
The αlpha pH 190 features two SPDT non-powered relays; rated for 6A at 110
VAC, 250 VAC maximum. When your process exceeds the set parameters of a
relay set point, the REL 1 or REL 2 indicator lights up.
To set parameters for relay 1 and relay 2, see Setup programs P1.0 and P2.0.
11 TRANSMITTER FUNCTION
If remote data logging is required, a 4-20 mA current loop can be connected. The
current will be proportional to the pH (or ORP) displayed on the panel display.
pH: 0.00 pH – 4 mA; 14.00 pH = 20 mA
ORP: -999 mV = 4 mA; 1000 mV = 20 mA
The 4-20 mA current loop can drive a load resistance of no more than 200 Ω.
12 ERROR MESSAGES
The following table provides a guideline to enable diagnosis of possible problems
indicated by the messages generated by the meter.
Error Message Indicates Possible Cause Corrective Action
Err1 Calibration
Error
Incorrect buffer solution used
or contamination of buffer
solution resulting to
calibration being attempted
outside the allowable
calibration window
Check if right
buffer solution
was selected or
use fresh buffer
solution.
Err2 Wrong
keypad input
When an invalid key is
pressed in a selected mode.
Select valid
operations
depending on the
selected mode.