Emerson PN 51-1055pHC/rev.K instruction manual Calibrating the Analyzer Conductivity

MODEL SOLU COMP II	SECTION 6.0
	CALIBRATION

6.10 CALIBRATING THE ANALYZER - CONDUCTIVITY.

6.10.1 Purpose

1.After a conductivity analyzer has been in service for a period of time recalibration may be necessary.

2.To check the calibration of the Solu Comp II, see Section 8.7. If the calibration does not meet specifications, the analyzer can be recalibrated according to Section 6.10.2.

3.To calibrate the Solu Comp II, replace the conductivity cell with a known resistance and make the analyzer reading match the resistor value. The resistor(s) used for calibration must be accurate to within ±0.1%.

6.10.2 Procedure

1.Use a standard resistor (accuracy ±0.1%) or a standard decade box (accuracy ±0.1%) for the calibration.

2.Choose the resistor based on the cell constant being used and the range of the measurement.

Cell constant	Conductivity (µS/cm)		Resistor (kΩ)
0.01	<0.5		100
	0.5 - 5.0		10
		>5	1
0.10	<0.5		1000
	0.5 - 5.0		100
	5	- 50	10
	>50		1
1.0		<5	1000
	5	- 50	100
	50	- 500	10
	>500		1
10	50	- 500	100
	500	- 5000	10
	>5000		1

Some of the conductivity values in the table are near the extreme ends of the recommended range for the cell constant. Refer to the table in Section 8.4.5 for recommended ranges.

3.Disconnect the sensor leads and connect the standard resistor or decade box to terminals 4 and 6 on TB5.

If a standard decade box is being used, keep the leads as short as possible (less than 5 ft). It is not necessary to disconnect the RTD leads.

60