Instruction manual

Instruction Manual PC 510
47
14 ADDENDUM 1: CONDUCTIVITY TO TDS CONVERSION FACTORS
1. Factor – the conductivity to ppm TDS conversion factor. Multiply conductivity by this factor to get
ppm TDS for the type of TDS reading needed.
2. 442 – a formulation that most closely represents the conductivity to ppm relationship, on average,
for naturally occurring fresh water. (4
0% NaSO
4
, 40% NaHCO
3
, 20% NaCl)
3. TDS Your Material – These columns are for you to write in your application-specific conductivity-
to-ppm values and conversion factors for future reference.
Factor = Actual TDS ÷ Actual Conductivity @ 25 °C
TDS KCl TDS NaCl
Conductivity at 25
°C
ppm Value Factor ppm Value Factor
84 µS
40.38 0.5048 38.04 0.4755
447 µS
225.6 0.5047 215.5 0.4822
1413 µS
744.7 0.5270 702.1 0.4969
1500 µS
757.1 0.5047 737.1 0.4914
8974 µS
5101 0.5685 4487 0.500
12,880 µS
7447 0.5782 7230 0.5613
15,000 µS
8759 0.5839 8532 0.5688
80 mS 52,168 0.6521 48,384 0.6048
TDS 442 TDS Your Material
Conductivity at 25
°C
ppm Value Factor ppm Value Factor
84 µS
50.50 0.6563
447 µS
300.0 0.6712
1413 µS
1000 0.7078
1500 µS
1050 0.7000
8974 µS
7608 0.8478
12,880 µS
11,367 0.8825
15,000 µS
13,455 0.8970
80 mS 79,688 0.9961