Sper Scientific 860031 pH - mV Bench-Top Meter - Manual (Page 61)

61
APPENDICES
APPENDIX A:
CONDUCTIVITY to TDS CONVERSION FACTORS
442 stands for:
40% sodium sulfate, 40% sodium bicarbonate and 20%
sodium chloride.
APPENDIX B:
CALCULATING TDS CONVERSION FACTORS
The meter can be calibrated using TDS calibration standard
solutions. The calibration standard requires the TDS value
at a standard temperature such as 25°C. To determine the
conductivity-to-TDS conversion factor, use the following
formula:
Factor=Actual TDS ÷ Actual Conductivity @ 25°C
Definitions:
Actual TDS: Value from the solution bottle label or from a
standard buffer, which is made using high purity water and
precisely weighted salts.
TDS KCl TDS NaCl TDS 442
ppm
value
Factor ppm
value
Factor ppm
value
Factor
1413 uS
2070 uS
2764 uS
8974 uS
12,880 uS
15,000 uS
80 mS
744.7
1045
1382
5101
7447
8759
52,168
0.527
0.5048
0.5
0.5685
0.5782
0.5839
0.6521
702.1
1041
1414.8
4487
7230
8532
48,384
0.4969
0.5029
0.5119
0.5
0.5613
0.5688
0.6048
1000
1500
2062.7
7608
11,367
13,455
79,688
0.7078
0.7246
0.7463
0.8478
0.8825
0.897
0.9961
Conductivity
at 25°C