Instruction Manual

ManualsBrandsYokogawa ManualsSensorsFU24 All-in-One pH/ORP Sensor

IM 12B6J3-03E-E

6.1 Calibration for pH measurement

To calibrate the FU24 pH/ORP sensor, two buffer solutions with known pH values

are required. It is recommended that one buffer solution has a value near to pH 7.00.

Depending on the process value to be measured, the second buffer solution should be

either acidic (below pH 7.00) or alkaline (above pH 7.00). Normally the IEC buffers (pH 4.01,

6.87 and 9.18) are used.

The following is a very general 2-point calibration procedure:

1. Clean the sensor using a 5% solution of HCl;

2. Rinse sensor thoroughly with demineralized water;

3. Immerse the sensor in the first buffer (pH 6.87 is recommended) and

execute calibration as described in the Instruction Manual of the analyzer.

4. Rinse sensor thoroughly with demineralized water;

5. Immerse the sensor in the second buffer (pH 4.01 or 9.18 is recommended)

and execute calibration as described in the Instruction Manual of the analyzer.

6. Rinse sensor thoroughly with demineralized water.

During calibration, the temperature compensation should be active.

The EXA/FLXA analyzer automatically compensates for the sensitivity change of the

pH sensor at different temperatures.

After calibration, replace or re-install the sensor into the process.

5.3 Settings for PH402G and PH202G(S)

Function pH

pH&ORP pH&rH ORP

pH compensated

Setting (default) ORP

code 01 0(pH) 0(pH) 0(pH) 1(ORP) 1(ORP)

code 02 0(off) 1(ORP) 2(rH) 0(off) 0(off)

code 03 1.1.1 1.1.1 1.1.1 0.0.1 0.0.1

code 04 0.0.1 0.0.1 0.0.1 0.0.1 1.1.1

code 31 0 2 2

jumper input 1 no no no yes yes

jumper input 2 yes yes yes yes no

5.4 Settings for PH150, PH450G and FLXA

Function pH

pH&ORP pH&rH ORP

pH compensated

Setting (default) ORP

sensor setup pH pH+ORP pH+ORP ORP ORP

measurement

setup

pH+ORP pH+rH

Impedance

setting

input1 High High High Low Low

input 2 Low Low Low Low High

jumper input 1 no no no yes yes

jumper input 2 yes yes yes yes no

6. GENERAL CALIBRATION & MAINTENANCE PROCEDURE