CENTRAL WATER
SOP 217
Standard Operating Procedure
USING THE TPS 2100 CONDUCTIVITY METER
1. Purpose
The procedures details how to:


Test conductivity using the TPS 2100 Conductivity Meter; and
Calibrate the TPS2100 Conductivity Meter.
2. Scope
This procedure is applicable to all TPS 2100 conductivity meters throughout the Authority.
3. Responsibility
3.1
Operations Manager – shall ensure that staff adheres to this procedure.
3.2
Water Quality Coordinator - shall ensure that:
•
3.3
All Plant Equipment is available, in good working order and used in accordance with the
manufacturers instructions.
Water Quality Team Member – shall:
•
•
•
Use TPS 2100 Conductivity Meters in accordance with this procedure;
Comply with all OHS requirements; and
Cleanup the work area ensuring all equipment is washed and ready for next use.
4. Procedure
4.1
Introduction
Conductivity is the capacity of ions in solution to carry electrical current. Current is carried by
inorganic dissolved solids with either a positive charge (cat ions such as sodium and magnesium) or
negative charge (anions such as chloride, nitrate and phosphate).
For this reason, conductivity and total dissolved solids (TDS) are terms that are often interchanged.
The basic unit of measurement for conductivity is the Siemen, with natural waters having
conductivities in the milli – micro Siemen range (mS - μS).
4.2
Testing Conductivity
USING THE TPS 2100 CONDUCTIVITY METER – SOP 217
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4.2.1
Preliminaries
1.
2.
Turn on TPS 2100 Conductivity Meter.
Ensure dials are set as in diagram 4.2.1.
4.2.2
Activity
EC Measurement





Collect sample
Carefully dry meter probe
Immerse probe in sample and gently stir
When digital reading settles take temperature of water
Using Conductivity Correction Factor.
Multiply TPS 2100 reading x Conductivity Correction Factor (See Appendix 1)
e.g. 0.331 (TPS reading) x 1.2 (CCF for 17°c)
= 0.331 x 1.2
= 0.397 mS
= 397 μS/cm
4.2.3 Monitoring Requirements
•
Record results on appropriate laboratory sheets or database.
4.2.4 Clean Up
•
•
Rinse all sample off probe using distilled water.
Store probe in distilled water.
USING THE TPS 2100 CONDUCTIVITY METER – SOP 217
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4.2
Calibration
Ensure the conductivity probe is free from contamination and is DRY.
•
•
•
•
•
Adjust the Zero control on the front of the meter to read 000 on the digital display.
Rinse a beaker with Conductivity Standard Solution and half fill.
Place the conductivity probe and thermometer in the beaker of standard solution.
Temperature of solution is not important, but highest accuracy is achieved if the solution
temperature is 25°C.
Adjust the calibration control to display the standard value.
Rinse the probe thoroughly in distilled water and dry. The instrument is now ready for
conductivity determination.
5.0
Documentation
5.1
Appendix 1: Conductivity Correction Factors
6.0
Definitions
6.1
Conductivity Standard Solution – a purchased standard solution with a known conductivity at a
known temperature
TPS 2100 digital conductivity meter
6.2
USING THE TPS 2100 CONDUCTIVITY METER – SOP 217
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CENTRAL WATER
APPENDIX 1
CONDUCTIVITY CORRECTION FACTORS
Multiplying Factors vs. Temperature to convert E-CT to E-C25
Temperature (C)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
07.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
16.5
17.0
17.5
Multiplying Factor (k)
1.78
1.76
1.74
1.72
1.70
1.68
1.66
1.64
1.63
1.61
1.59
1.57
1.55
1.53
1.52
1.50
1.48
1.47
1.45
1.43
1.42
1.40
1.38
1.37
1.35
1.34
1.32
1.31
1.29
1.28
1.26
1.25
1.23
1.21
1.20
1.29
USING THE TPS 2100 CONDUCTIVITY METER – SOP 217
Temperature (C)
18.0
18.5
19.0
19.5
20.0
20.5
21.0
21.5
22.0
22.5
23.0
23.5
24.0
24.5
25.0
25.5
26.0
26.5
27.0
27.5
28.0
28.5
29.0
29.5
30.0
30.5
31.0
31.5
32.0
32.5
33.0
33.5
34.0
34.5
35.0
Multiplying Factor (k)
1.18
1.17
1.15
1.14
1.12
1.11
1.10
1.09
1.08
1.06
1.05
1.04
1.03
1.01
1.00
1.99
1.98
1.97
1.96
0.95
0.94
0.93
0.91
0.90
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.80
0.79
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