product overview

Antimony electrode acidity transmitter is an industrial online analytical instrument that integrates pH measurement, automatic cleaning, and electrical signal conversion. Suitable for continuous pH measurement and control in industries such as chemical, metallurgical, pharmaceutical, papermaking, sugar manufacturing, and environmental protection.

Product Features

The patented pressurized pH sensor, under the push of elastic pressure greater than 100KPa in the inner cavity, makes it difficult for the internal reference solution to seep out from the microporous salt bridge, and its forward seepage lasts for more than 20 months

The dual high resistance circuit composed of the third electrode grounded can effectively overcome interference and achieve a precise and stable measurement system

The long-term stable reference potential ensures the reliability of the measurement system, and its service life is 3-5 times that of the gel electrode

VP connector, sturdy, waterproof, and compliant with IP68 standards, ensures reliable connection between sensors and cables in harsh industrial environments

Direct installation of pipe threads, three-way installation, circulation pool, float type, etc., with various installation methods, suitable for different on-site environments

Product Technical Parameters

The electronic conversion unit adopts a modular structure, which is earthquake resistant, moisture-proof, and has a low failure rate

The technology of "integrated acidity sensor" and "thin film salt bridge device" using high-purity antimony as the measuring electrode and silver silver chloride ring electrode as the reference electrode has obtained two national patents (patent number• X, ZL932017533)

The scraper blade mechanical cleaning device can clean the measuring electrode and reference electrode simultaneously, with good anti scaling ability. It can work continuously for a long time in media with high turbidity, high viscosity, easy crystallization or scaling without maintenance

The internal reference solution high-temperature tank ensures that the reference electrode is not contaminated by reverse osmosis, the reference potential is stable, and the drift is small

Equipped with XM series indicator regulator, it has DC24V output and can directly provide power to the motor

Measurement principle:

A pH measurement system consisting of an antimony electrode and a reference electrode produces an antimony trioxide (Sb2O3) oxide layer on the surface of the antimony electrode in the measured solution. A potential difference is formed between the metal antimony and antimony trioxide, and the magnitude of the potential difference depends on the concentration of antimony trioxide, which corresponds to the activity of hydrogen ions (H+) in the measured solution.

The corresponding relationship between antimony electrode potential and hydrogen ion concentration varies in different solution systems, generally between 45~50mV/pH. Therefore, it is recommended to use on-site calibration methods for antimony electrode transmitters.

Selection precautions:

Antimony electrode acidity transmitter is particularly suitable for harsh processes such as high viscosity and crystallization, and can work normally in media that glass electrodes cannot handle. The disadvantage is that there is a large nonlinear error in the pH range below 2 and above 12. When selecting, it should be noted that it is best to use it in the range of 2-12pH, and its performance is good in the range of 4-10pH.

The structure of antimony electrode acidity transmitter is complex, including motor, reducer, transmission mechanism, sealing structure, antimony electrode reference electrode, and a relatively higher failure rate than glass electrode. Therefore, in general, glass electrode acidity transmitter should be preferred.

1. Wiring instructions

Hosman plug wiring instructions

Please wire the Hosman plug according to the following diagram

1. Unscrew the screw and pull out the plug upwards

2. Pry open the plug and follow the wiring diagram to connect the wires.

Aluminum alloy junction box wiring instructions?

Transmitter inspection

Standard buffer solution is generally used for testing. The method is to first calibrate the neutral point (near PH7) with a standard solution with a pH of 6.86. The transmitter output should be 12mA (4-20mA) or 5mA (0-10mA), and the error can be eliminated by adjusting the positioning potentiometer. (Adjust the "O" potentiometer on the circuit, increase clockwise and decrease counterclockwise). Use PH4.01 standard solution to test the acidity point, and the transmitter output is 4.01 × 1.142+4=8.58mA (4-20mA). The error can be eliminated by adjusting the slope potentiometer. (Adjust the "S" potentiometer on the circuit) Finally, place the transmitter probe in a standard solution with pH 9.18. The transmitter output should be 9.18 × 1.142+4=14.48mA (4-20mA), and the difference between its reading and the standard is the instrument error.

Please note during inspection that when testing one solution before testing another, the probe must be cleaned with a solution with the same pH value as the solution being tested, otherwise it will introduce significant inspection errors.

Figure 3PHThe correspondence between values and input/output signals

Installment and use

1. After unpacking the instrument, check for any damage, leakage, or looseness (the reference salt bridge around the glass electrode is allowed to have salt crystallization).

2. When connecting a two-wire transmitter to a computer, adjusting a recorder, printer, or other secondary instruments, an isolated distributor or XMT or XMZ-1000 series display instrument with isolated output produced by our company must be equipped. The required 4-20mA signal is obtained from its output terminal to isolate the common ground interference between the measurement system and the output to the secondary instrument. (For a pH transmitter, the electrode system must be connected to the ground, and in order to function properly, the external connection must be suspended and well insulated from the ground. However, most computers or regulating recording instruments are grounded from the power supply, and after being directly connected to the transmitter, the transmitter's circuit is grounded to form a two-point grounding of the measurement circuit, resulting in the electrolysis of the reference electrode and failure.)

3. After the wiring is completed and checked for errors, the terminal cover and wire pressing screws of the junction box must be tightened to ensure good sealing of the junction box. When severely damp, it will cause abnormal output

4. Connect the transmitter wires (distinguish between 24V power supply and 220V power supply!)

The probe should be placed in clean water and the displayed value should be around PH7 when powered on. During transportation, bubbles may accumulate inside the glass electrode measuring bulb, resulting in abnormal output values. At this point, the sensor can be placed upright and lightly tapped on the probe part with your hand until no bubbles are visible inside the measuring bulb. If the reading is slightly lower with a little acid, it is basically normal. Do not adjust it in a hurry. Soak it for more than 24 hours to reduce and stabilize the unbalanced potential before verifying.

5. Please refer to the special instructions for inspection

6. The installation and wiring of the transmitter are shown in Figure 4 or Figure 5 (stamped type pH meter)

Figure 4: Wiring Diagram

6. Instruments should be inspected regularly according to the condition of the measured medium. If the medium condition is good, it can be inspected every six months. If scaling or pollution is severe, it should be inspected and cleaned once a month or even once or twice a week. Even if there is an automatic cleaning device, it should be checked regularly.

7. The lower end of the transmitter junction box is a reference solution high-level tank, which is connected to the measured solution through a salt bridge structure and may have slight losses. When the reference solution drops significantly, it should be replenished once every six months to a year. For those with pressure compensation devices, it should be noted that the pressure indication value should not be lower than the medium pressure to prevent reverse osmosis pollution of the reference electrode. Regular inflation and pressurization can be carried out.

★ 8. Glass electrodes are consumables with a service life of about one year. The usage time of the electrode is closely related to the water condition of the measured medium and whether the cleaning and maintenance are sufficient. If the water condition is poor or not cleaned properly, the service life of the electrode will be greatly reduced. Therefore, glass measuring electrodes are not covered by warranty.