Toxic gas detector, this professional term sounds a bit unfamiliar, and it is not accessible in ordinary life, so we know very little about this knowledge, but in some specific industries, this kind of equipment is needed to perform its operation. Given the function, let’s walk into this strange world of nouns and learn some safety knowledge.
Toxic Gas Detector – Used to detect toxic gases (ppm) in the surrounding atmosphere. Gases such as carbon monoxide, hydrogen sulfide and hydrogen can be detected. Toxic gas detectors are divided into intrinsically safe toxic gas detectors and flameproof toxic gas detectors. Intrinsically safe products are intrinsically safe products that can be used in highly hazardous situations.
Features: 0, 2, 4~20, 22mA current output/Modbus bus signal; automatic protection function against high-concentration gas shock; high-precision, anti-poisoning imported sensor; two cable inlets, convenient for on-site installation; independent gas chamber The structure and sensor are easy to replace; a set of programmable linkage output interfaces; automatic zero tracking and temperature compensation; the explosion-proof grade is ExdⅡCT6.
Working principle: The combustible/toxic gas detector samples the electrical signal on the sensor, and after internal data processing, outputs a 4-20mA current signal or Modbus bus signal corresponding to the surrounding gas concentration.
Toxic gas detectors in fire fighting equipment are most often installed in petrochemical enterprises. What is the installation specification for toxic gas detectors in the “Code for Design of Flammable Gas and Toxic Gas Detection and Alarm in Petrochemical Enterprises” stipulated by state agencies? The installation specifications for toxic gas detectors are listed below to provide a guide for everyone to install toxic gas detectors.
SH3063-1999 “Petrochemical Enterprises Combustible Gas and Toxic Gas Detection Alarm Design Specification” points out:
1) Toxic gas detectors should be installed in places with no impact, vibration, and strong electromagnetic field interference, and a clearance of no less than 0.3m should be left around.
2) When detecting toxic and harmful gases, the detector should be installed within 1m from the release source.
a. When detecting toxic and harmful gases lighter than air such as H2 and NH3, the toxic gas detector should be installed above the release source.
b. When detecting toxic and harmful gases heavier than air such as H2S, CL2, SO2, etc., the toxic gas detector should be installed below the release source.
c. When detecting toxic and harmful gases such as CO and O2 whose specific gravity is close to that of air and easily mixed with air, it should be installed in a space that is easy to breathe.
3) The installation and wiring of toxic gas detectors shall comply with the relevant provisions of GB50058-92 “Code for Design of Electric Power for Explosion and Fire Hazardous Environments” in addition to the requirements specified by the manufacturer.
In short: the installation of toxic gas detectors should be within a radius of 1 meter near the leak-prone places such as valves, pipe interfaces, and gas outlets, as close as possible, but do not affect the operation of other equipment, and try to avoid high temperature, high humidity environment and external influences (such as splashing water, oil and the possibility of mechanical damage.) At the same time, it should be considered for easy maintenance and calibration.
In addition to paying attention to the correct installation and use of toxic gas detectors, machine safety maintenance is also an aspect that cannot be ignored. Fire-fighting equipment has a certain lifespan, and after a period of use, there will be problems of one kind or another, and the same is true of toxic gas detectors. After installing a toxic gas detector, some common faults may occur after running for a period of time. When encountering a fault, you can refer to the following methods.
1. When the reading deviates too much from the actual, the cause of the failure may be the change of sensitivity or the failure of the sensor, and the sensor can be re-calibrated or replaced.
2. When the instrument fails, it may be the wiring loose or short circuit; the sensor is damaged, loose, short circuit or high concentration, you can check the wiring, replace the sensor or recalibrate.
3. When the reading is unstable, it may be due to air flow interference during calibration, sensor failure, or circuit failure. You can recalibrate, replace the sensor, or send it back to the company for repair.
4. When the current output exceeds 25mA, the current output circuit is faulty, it is recommended to send it back to the company for maintenance, and other faults can also be sent back to the company for maintenance.
Post time: Jun-06-2022