Online Conductivity Meter _ Industrial Online Conductivity Meter

Overview

Industrial online conductivity meter (hereinafter referred to as the instrument) is a water quality online monitoring instrument with a microprocessor. This instrument is equipped with conductivity electrodes of different types and constants, used for continuous monitoring and control of the conductivity and temperature values of aqueous solutions. Widely used in power plants, petrochemicals, metallurgy, paper industry, environmental water treatment, light industry electronics and other fields. Monitoring and control of raw and produced water quality for water production equipment such as power plant cooling water, make-up water, saturated water, condensate water and boiler water, ion exchange, reverse osmosis EDL, seawater distillation, etc.

The instrument adopts LCD liquid crystal display screen; Intelligent Chinese menu operation; Equipped with current or voltage output, freely adjustable measurement range, high and low limit alarm prompts, and two sets of relay control switches, with adjustable hysteresis range; Automatic or manual temperature compensation;

According to user needs, conductivity electrodes can be installed in various forms such as flow type, pipeline type, sinking type, flange type, etc.

II. Structural Features and Working Principles

1. Structural features:

The entire measurement system mainly consists of two parts: instruments (secondary meters) and conductivity electrodes (primary meters). The electrodes are in contact with the measured solution, and the instruments display the conductivity value, temperature, and working status of the measured aqueous solution.

2. Working principle:

Measurement principle: To avoid electrode polarization, the instrument generates a highly stable sine wave signal that is applied to the electrode. The current flowing through the electrode is proportional to the conductivity of the measured solution. The instrument converts the current from a high impedance operational amplifier to a voltage signal, which is amplified by a programmable signal amplifier, phase sensitive detection, and filtering to obtain a potential signal reflecting the conductivity; The microprocessor alternately samples the temperature signal and conductivity signal through switch switching, and after calculation and temperature compensation, obtains the conductivity value and temperature value of the measured solution at 25 ℃.

Temperature compensation principle: The conductivity of electrolyte solution is affected by temperature changes and requires temperature compensation. The temperature coefficient of a weak aqueous solution is 2.00% ℃, and the higher the concentration, the smaller the temperature coefficient. The temperature coefficient for solutions with lower concentrations (1 µ S · cm-1) is not set at 2.00% ℃, but is set by the user within the range of 0.00-99.9%.

Three technical parameters

(1) Measurement range (range can be freely set):

Conductivity: 0-20 µ S · cm-1 (K=0.01); 20～200µS·cm-1 （K=0.1）；

200µS·cm-1～4mS·cm-1 （K=1.0）； 4～20.0mS·cm-1 ； （K=10.0）

20～100.0mS·cm-1 ； （K=30.0）

Temperature: -5~110 ℃;

(2) Resolution: Conductivity: 0.01 µ S · cm-1; 0.01 mS · cm-1; Temperature: 0.1 ℃;

(3) Basic instrument error: conductivity: ± 1.0% F · S ± 1 word, temperature: ± 0.5 ℃;

(4) Automatic or manual temperature compensation range of electronic unit: 0-110 ℃ (reference temperature 25 ℃);

(5) Automatic temperature compensation error of electronic unit: ± 0.5% F · S;

(6) Electronic unit stability: ± 0.2% F · S ± 1 word/24h;

(7) Repetitive error of electronic unit: ≤ 0.2% F · S ± 1 word;

(8) Electronic unit alarm error: ± 1% F · S;

(9) Electronic unit output current error: ± 1% F · S;

(10) Signal output: 0-10mA (load resistance<1.5K Ω); 4-20mA (load resistance<750 Ω);

0-5V, 0-10V optional (reservation required);

(11) Two sets of relay control contacts: 3A 240VAC, 6A 28VDC or 120VAC;

(12) Power supply: 220VAC ± 10%, 50 ± 1Hz, power ≤ 3W;

24VDC， Power ≤ 1W (to be reserved); 12VDC， Power ≤ 1W (to be reserved);

(13) Dimensions: 96 × 96 × 130mm;

(14) Installation method: disk mounted (embedded); Hole size: 91 × 91mm;

(15) Wall mounted: Waterproof wall mounted box size: 300 (height) x 200 (width) x 167 (depth) mm;

(16) Instrument weight: 0.6kg;

(17) Work environment:

1) Environmental temperature: -10~60 ℃; 2) Relative humidity: not exceeding 90%;

3) There is no strong magnetic field interference around except for the Earth's magnetic field.