Thermo Fisher Scientific CyberScan PC 510 - Manual (Page 51)

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. (40% 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