Select instruments based on the range of measured values.
Measurement of the electrical conductivity of regular water and wastewater requires electrodes with a constant of 1 (1 μS/cm to 1 S/cm). For low conductivity values (below 10 μS), optional pure water electrodes with a constant of 0.1 pure water electrode (0.001-200 μS/cm) can be used; or electrodes with a constant of 0.01 ultra-pure water (0.0001-30 μS/cm) should be used, along with a sealed circulation cell.
2. Based on the measured environmental conditions or specific requirements
Portable, desktop, and online instruments available for selection.
Choose based on the convenience of the instrument.
Currently, general instruments on the market lack functions like electrode data saving. Electrodes require recalibration. WTW pure and ultra-pure water electrodes do not need recalibration, as their constants are constant. WTW digital IDS electrode calibration data is stored on the electrode, so there's no need for recalibration when replacing either the electrode or the main unit.
4. Select measurement instruments based on their functionality and cost-performance ratio.
When prices are relatively similar, it is advisable to prioritize intelligent instruments that are easy to operate, come with automatic storage settings and data calibration, automatic range conversion, automatic temperature compensation, and temperature measurement, among other practical features.
5. Select based on the required measurement accuracy
The accuracy level of a conductivity meter is determined by the ratio of the maximum error to the full-scale value, known as the "reference error." For instruments with 0.5, 1.0, 1.5, and 2.0 levels, the respective reference errors are 0.5%, 1.0%, 1.5%, and 2.0%. If the instrument's full scale is 200μs/cm, a 2.0-level instrument has a maximum test error of ±4μs/cm. If the full scale is 20μs/cm, the 2.0-level instrument's maximum test error is ±0.4μs/cm. Users should select an appropriate level of conductivity meter based on the required measurement accuracy. Additionally, for manually switched multi-range instruments to achieve the minimum test error, it is advisable to test in the lowest range setting.
News Center Co., Ltd.
