User Guide

Instruction Manual CON 510
5
4 CALIBRATION
4.1 Important Information on Meter Calibration
The CON 510 bench meter allows you to perform automatic calibration (only for Conductivity mode) or manual calibration
(applicable to both Conductivity/TDS mode). The meter can calibrate either single point or multi-point up to 5 calibration
points (manual mode) with a maximum of 1 point in each measurement range. Use single-point automatic calibration
when calibrating using Conductivity standard calibration solutions (as mentioned in Section 4.6) as it suffices.
When calibrating using uncommon or non-standard Conductivity/TDS calibration solutions which are freshly prepared,
use the manual calibration option as it allows you to manually set to the desired value to match the standards being
used. However if you are measuring sample values in more than one range, it is recommended to calibrate each of the
ranges which you are measuring to ensure best meter accuracy.
• If you are measuring in ranges near to or greater than 20 mS (10 ppt if TDS factor is set to 0.5), or near to or
lower than 100 µS (50 ppm), calibrate the meter at least once a week to get specified ±1% Full Scale accuracy.
• If you are measuring in the mid-ranges and you washed the probe in de-ionized water and stored it dry,
calibrate the meter at least once a month.
• If you take measurements at extreme temperatures, calibrate the meter at least once a week.
For best results, select a standard value close to the sample value you are measuring. Alternatively, use a calibration
solution value that is approximately 2/3 the Full-Scale value of the measurement range you plan to use. For example, in
the 0 to 2000 µS/cm conductivity range, a 1413 µS/cm solution is a good solution for calibration.
The following table lists all the corresponding conductivity and TDS ranges. You should calibrate each range using a
suitable standards solution that falls between the values in the “recommended calibration solution range” column.
Range
Indicator
Conductivity
Range
Recommended
Calibration Solution
Range
TDS
Range
Recommended
Calibration Solution
Range
r 1
0 – 20.00 µS/cm 6.00 - 17.00 µS/cm 0 – 10.00 ppm 3.00 - 8.50 ppm
r 2
0 – 200.0 µS/cm 60.0 - 170.0 µS/cm 0 – 100.0 ppm 30.0 - 85.0 ppm
r 3
0 – 2000 µS/cm 600 - 1700 µS/cm 0 - 1000 ppm 300 - 850 ppm
r 4
0 – 20.00 mS/cm 6.00 - 17.00 mS/cm 0 – 10.00 ppt 3.00 - 8.50 ppt
r 5
0 – 200.0 mS/cm 60.0 - 170.0 mS/cm 0 - 100 ppt 30.0 – 85.0 ppt
When you recalibrate your meter, old calibration values are replaced on that specific measurement range. For example,
if you previously calibrated the meter at 1413 µS/cm in the 0 - 2000 µS/cm range and you recalibrate at 1500 µS/cm (in
the same range of 0 - 2000 µS/cm), the meter will replace old calibration data (1413 µS/cm) in that range if the meter is
in the multi-point calibration mode and the meter will retain all calibration data in other ranges. Or else, the calibration
data replaces with new data for all ranges (in single-point calibration mode).
To view calibrated solutions and its corresponding cell constants at respective range, see SETUP main-menus P1.0 and
P2.0.
To completely recalibrate your meter, or when you use a replacement probe, it is best to clear all the calibration data in
the meter’s memory. To erase all the old conductivity and TDS calibration data completely from memory, see SETUP
main-menu P7.0.
Temperature Coefficient: This meter is factory set to a temperature coefficient of 2.1 % per °C. For most applications
this will provide good results. See SETUP sub-menu P4.1 to set the temperature coefficient to different value. See also
Addendum 2, “Calculating Temperature Coefficients” to determine the appropriate temperature coefficient for your
solution.