Industrial Online Conductivity Meter Calibration

Conductivity represents the conductivity of various ions in aqueous solution. It can be used to represent the total amount of various ions. It is accurate, simplifies the detection method, and can measure on-line, monitoring the working condition of the wastewater treatment system at any time. The newly-installed on-line conductivity meter has a new host and conductivity cell. After installation and debugging at the factory site, the accuracy is relatively reliable. However, when the on-line conductivity meter has been in operation for a long time, especially when the conductivity cell is immersed in the treated wastewater for a long time, it tends to age. In this way, for some reason, some of the treated water that cannot meet the discharge standard can be due to the reaction of the conductivity cell. Oblivious, misunderstood that it can be discharged, and it will be passed. How many tons of waste water that will not reach the standard will be injected into the Minjiang River each year? Nominally there are instruments that monitor the discharge of waste water. Actually, they are in fact useless. There is nothing worse than nothing. Today, when it comes to advocating environmental protection, it is particularly important to calibrate the on-line conductivity meter.

The solutions to these three problems are described separately below:

(1) At the beginning of this work, it was found that most of the electrodes were already aging, and the measured data was basically unreliable. It is recommended that the manufacturers change their batteries.

(2) Solve the problem of excessively large probe cell volume: Remove the probe from the sewage ditch and put it into the bucket to clean it. Carefully remove the probe cover and restore it to the size of the bench conductivity meter conductivity cell; (3) To solve the dirty problem of the conductivity cell probe: wipe the cleaned conductivity cell probe gently with cotton, rinse with distilled water, and dry the test paper;

(4) Solve the problem of measuring range:

Because only the standard solution of 147.7μs/cm (25°C) was purchased from the national standard center, it is only possible to measure the on-line conductivity meter of this range from 0 to 200.00μs/cm, and it cannot measure the range of 0 to 20.00μs/cm. Online conductivity meter, what should I do? Let the customer buy a new 0.2-grade portable conductivity meter and measure the host to 0.2 with the conductivity meter tester, that is, the electricity meter reaches 0.2, and then measure the conductivity cell with the conductivity standard solution. Machine matching error, see if it also reached 0.2. When both items reach level 0.2, they are ready for use. Use this newly purchased conductivity meter to match the standard solution in the 0 to 20.00 μs/cm range to solve the span problem.

It is much more convenient to calibrate after being prepared. Place the conductivity cell directly into the standard solution, place different standard solutions in different ranges, read the data, and see a bit of error. Find the CHECK point. Use a screwdriver to adjust the number and standard of the panel. The standard value of the solution is basically the same, fast and accurate, and won praise from users.

First, the conductivity meter verification procedures for the conductivity meter requirements From the verification procedures can be seen, on-line conductivity meter as long as the detection of the instrument quoted error is enough. The conductivity of the conductivity standard solution measured by an on-line conductivity meter conductivity cell should not exceed ±4.5% FS. Otherwise, the on-line conductivity meter must be adjusted to meet the measurement requirements.

Second, the calibration of the on-line conductivity meter First, a brief introduction of industrial conductivity meter products. The conductivity monitor can continuously measure and monitor the conductivity value of purified water and general aqueous solution for a long period of time and is suitable for on-line conductivity monitoring in the general industry.

Product introduction and technical parameters

Conductivity monitor can continuously measure and monitor the conductivity value of pure water and general aqueous solution for a long period of time. It adopts open-hole plug-in installation and has a temperature drift automatic compensation circuit to ensure the measurement accuracy of the product. It is widely used in ion exchange. , Reverse osmosis EDI and other water production equipment, raw water and water quality measurement, monitoring.

The main technical performance measurement range: 0 ~ 2000μs/cm, divided into:

0～20.00μs/cm

0～200.00μs/cm

0～2000μs/cm three ranges:

Display mode: 31/2 digit, 0.5′′ LCD conductivity direct reading display (with backlight display);

Temperature compensation: automatic temperature compensation, compensation base 25 °C, compensation range 0 °C ~ 60 °C;

Measurement accuracy: ± 2% (FS);

Electrode configuration: 1.00cm-1 plastic foil gold electrode. 4' pipe thread connection, wire length 5 meters;

Signal output: 4～20mA current signal (optional upper limit alarm output);

Dimensions: Panel Size: 100*52 (mm)

Opening size: 91*45(mm);

Instrument depth: 100 (mm);

Instrument power supply: AC220V ± 10%, 50Hz;

Instrument working conditions: ambient temperature: 0 °C ~ 40 °C;

Relative humidity: ≤85%;

Medium temperature: 0 °C ~ 50 °C;

Product inspection basis: JB/T6855.

Second, the Conductivity Meter Verification Requirements for Conductivity Meters. From the verification procedures, it can be seen that the on-line conductivity meter only needs to detect the instrument reference error. The conductivity of the conductivity standard solution measured by an on-line conductivity meter conductivity cell, the instrument reference error should not be greater than ± 4.5% FS, otherwise the on-line conductivity should be adjusted to meet the measurement requirements.

Third, the calibration of the on-line conductivity meter to be discharged. Through investigation and research, we found the following problems:

(1) Electrode aging;

(2) Oversized probe cell volume;

(3) The conductivity cell probe is too dirty;

(4) Question of range.