59
9900 Transmitter
Manual Calibration Procedure - ORP
Requires prepared buffers and a prepared quinhydrone solution:
Saturate 50 mL of pH 4 (264 mV) and 7 (87 mV) buffers with 1/8 g quinhydrone or
Light's Solution (476 mV).
(System calibration is possible with two known ORP solutions,
but use a buffer close to your own process value).
NOTE:
ORP solutions made with quinhydrone are very unstable and
may not read properly once exposed to air for a prolonged time.
These solutions must be disposed of within an hour.
The solution can be used for calibrating more than one sensor.
However, the solution must remain free of debris and must not be
diluted by rinse water from previous calibrations.
Single-point calibration
sets STANDARD only;
Signet recommends a
two-point calibration to
set SLOPE in addition
to STANDARD.
Quick Manual Calibration
Procedures:
1-Point Calibration
:
1. Set solution standard.
2-Point Calibration
(recommended):
1. Set solution standard.
2. Set solution slope.
Acceptable ranges for the readings are ± 80 mV (i.e., 87 ± 80 mV).
ENTER
30s
30s
ENTER
ENTER
ENTER
+
Allow for stabilization
30 seconds to
several minutes
to accept
Display returns to
VIEW Mode
To Calibrate:
To Change Reading:
To Set Slope:
To Set Calibration Date:
Place electrode tip in
saturated pH 7.0 buffer.
pH 7.0 = 87 mV
Place electrode tip in
saturated pH buffer two
pH units different than
standard.
pH 4.0 = 264 mV
To Change Reading:
to accept
to accept
to accept
Allow for stabilization
30 seconds to
several minutes
Calibration Procedures - ORP
