Extech Instruments EC150 User Manual

10 EC150-EU-EN-V2.0-9/11
Appendix A: Factory Default Settings
Type Parameter Default Notes
P1.1 Select °C/°F °C Temperature units
P1.2 Normalized Temperature (reference temperature) 25°C Select 20°C or 25°C
P1.3 Temperature Coefficient 2.1% / °C Adjust from 0.4 to 10%
P2.1 TDS Factor 0.50 Adjust from 0.40 to 1.00
P3.1 Revert to Factory Default settings NO Select YES to revert to default settings
P4.1 ----- Calibration Data for Range 1
P4.2
Review previous Calibration data
----- Calibration Data for Range 2
Appendix B: Conductivity to TDS Conversion Factors
TDS KCl TDS NaCl TDS 442* Conductivity at
25°C
ppm Factor ppm Factor ppm Factor
23 µS 11.6 0.5043 10.7 0.4652 14.74 0.6409
84 µS 40.38 0.4807 38.04 0.4529 50.5 0.6012
447 µS 225.6 0.5047 215.5 0.4822 300 0.6712
1413 µS 744.7 0.527 702.1 0.4969 1000 0.7078
1500 µS 757.1 0.5047 737.1 0.4914 1050 0.7
2070 µS 1045 0.5048 1041 0.5029 1500 0.7246
2764 µS 1382 0.5 1414.8 0.5119 2062.7 0.7463
8974 µS 5101 0.5685 4487 0.5 7608 0.8478
12,880 µS 7447 0.5782 7230 0.5613 11,367 0.8825
15,000 µS 8759 0.5839 8532 0.5688 13,455 0.897
80mS 52,168 0.6521 48,384 0.6048 79,688 0.9961
*442: 40% sodium sulfate, 40% sodium bicarbonate, and 20% chloride
Appendix C: Calculating TDS Conversion Factors
This meter can be calibrated using TDS calibration standard solutions. The calibration requires the
TDS value at a standard temperature such as 25°C. Note that the TDS calibration can be
performed using the conductivity calibration (detailed earlier in this user guide) and thereafter
using a conductivity-to-TDS conversion factor. To determine the Conductivity-to-TDS conversion
factor, use the following formula:
Factor = Actual TDS / Actual Conductivity at 25°C
Where the Actual TDS is the value from the solution bottle label or from a standard buffer made
using high purity water and precisely weighed salts. Actual Conductivity is the measured value
using a calibrated Conductivity/TDS/Temperature meter.
Both the Actual TDS and the Actual Conductivity values must be in the same magnitude of units.
For example, if the TDS value is ppm, the Conductivity value must be in µS; if the TDS value is n
ppt, the Conductivity value must be in mS.
Check this by multiplying the conductivity reading by the factor in the above formula; the result is
the TDS in ppm.
Refer to the Setup section of this User Guide for instructions on programming the TDS factor.
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Extech Instruments EC150 Specifications

Measurement Ranges

conductivity range	0 to 1999µS and 0 to 19.99mS
TDS range	0 to 1999ppm and 0 to 19.99ppt

Accuracy and Resolution

conductivity and TDS accuracy	1% Full Scale ±1digit
conductivity resolution	1µS and 0.01mS
TDS resolution	1ppm and 0.01ppt
temperature accuracy	±0.5°C
temperature resolution	0.1°C/°F

Power

auto power off	After 20 minutes of inactivity
power supply	Four (4) LR44 ‘button’ batteries

Dimensions

dimensions	165 x 35 x 32mm (6.5 x 1.4 x 1.3”)