What Is a Hydrogen Sulfide Detector?

Semiconductor technology hydrogen sulfide gas detector is designed to monitor the concentration of hydrogen sulfide gas in the ambient air. Its measurement range is from the standard 0-20 / 50 / 100ppm (adjustable at the work site) to the high measurement range 10,000 ppm. This product uses solid metal oxide semiconductor sensing technology. The sensor consists of two sheets: one is a heating sheet and the other is a gas-sensitive sheet that is sensitive to hydrogen sulfide gas. Both wafers are mounted on a silicon chip by vacuum coating. The heating plate raises the working temperature of the gas-sensitive plate to a level capable of reacting with hydrogen sulfide gas. There are metal oxides on the gas sensitive sheet, which can dynamically show the change of hydrogen sulfide gas concentration. Its sensitivity can range from one-billionth to one-hundredth. This product is sturdy and durable, and can maintain stable work for more than ten years in most industrial environments.

Hydrogen sulfide detector

Right!

Semiconductor technology

l Rugged and durable, with strong resistance to severe weather

l Long service life

The longest warranty period for hydrogen sulfide gas detectors in the world

l Low replacement and maintenance costs

l Not affected by prolonged exposure to hydrogen sulfide

Where are solid oxide semiconductor type hydrogen sulfide detectors most suitable?

Bad weather

l Desert and high temperature area

l Sub-zero environment

l Tropical and subtropical humid environment

Harsh environment

l Ocean operations

l Oil and gas drilling operations

l Where hydrogen sulfide gas often appears

1. (Standard 4-20MA output)

It is an explosion-proof detector with a hidden cover. Operation is via a pointer meter on the signal transmitter faceplate. The product was sold in 1985, and there have been design improvements over the years. One of the latest improvements is the addition of troubleshooting features. The fault diagnosis circuit can trigger the light-emitting diode when the heater or gas sensor is disconnected and synchronously change the 4-20mA output to 0mA. The plug-in module of the sensor signal generation circuit facilitates the upgrading of the product.

l Linear 4-20mA output

l Sensor fault diagnosis

l Direct response, constant temperature control

l Single person remote calibration

l Field upgradeable according to MicroSafe smart detector standard

2,

(Intelligent sensor, 4-20mA output, interference-free operation interface)

Smart Detector Application Software Technology. The programming buttons under the glass cover can be operated via a hand-held magnetic programming tool. Interactive, continuous calibration prompts are displayed on a 16-bit LCD display. The transmitter is designed with integrated diagnostic functions. Every situation is easily displayed. The signal transmission module of the sensor is plug-in, which facilitates on-site maintenance. The TP-524 transmitter can be used to replace the existing one.

l Linear 4-20mA output

l Integrated sensor fault diagnosis

l Direct response, constant temperature control

l Single person remote calibration

l With sensor working life display

l LCD display failure and calibration status

l Non-interference control interface (via handheld magnetic programming tool)

l Simple menu programming and calibration

l 16-bit character LCD display with backlight

3.

(Intelligent sensor, 4-20MA output, RS-485 communication interface, relay-free operation interface) The intelligent detector is the most complete hydrogen sulfide sensor. This intelligent sensor applies software technology. Use interference-free operation interface. All operations are menu-driven and can be performed with a handheld magnetic programming tool. Provides flexible options in system establishment. Standard output includes 4-20mA output, RS-485 communication interface and 3 alarm relays. The sensor's signal transmission module is plug-in, which facilitates on-site maintenance.

l Linear 4-20mA output, 3 alarm relays and RS-485 communication interface

l Integrated sensor fault diagnosis

l Direct response, constant temperature control

l Single person remote calibration

l With sensor working life display

l LCD display failure and calibration status

l Non-interference control interface (via handheld magnetic programming tool)

l Simple menu programming and calibration

l 16-bit character LCD display with backlight

l Field-replaceable plug-in electronic components

The signal generator components of all TP series sensors are equipped with multi-pin plugs to facilitate quick replacement or upgrade on the job site. The gold-plated plug guarantees maximum corrosion resistance, and the sealed design provides moisture protection for the sensor.

Simple calibration The initial calibration of the sensor is automatic, just press twice on the handheld magnetic programming tool and take three minutes. No zero adjustment is required. The remaining life of the sensor is displayed during each calibration.

l Intuitive user interface

In addition to the initial calibration, the user interface can also perform measurement range adjustments, heating and gas sensor voltage adjustments, calibration gas value adjustments, and alarm point adjustments. The "View Program Status" function on the display (ie, "See Program Status") displays all current parameters for viewing.

l Temperature and humidity limits

Solid oxide semiconductor sensors are more adaptable to temperature and humidity than any other sensor. It is ideal for tropical, desert and other harsh climates.

l Recovery speed after hydrogen sulfide test

The solid oxide semiconductor type sensor can withstand high concentrations of hydrogen sulfide exposure, and it can quickly recover without harming its function. Electrochemical hydrogen sulfide sensors may be poisoned and permanently damaged by prolonged continuous exposure.

l Long-term quality assurance / low purchase and maintenance costs

The solid oxide semiconductor sensor is the industry's longest warranty period for hydrogen sulfide sensors. The company's ten-year proportional quality guarantee saves users from the cost of expensive sensor replacement. In ten years, the replacement cost of semiconductor sensors only accounted for 26% of electrochemical sensors.

The hydrogen sulfide sensor provides users with many options for output signal selection. Multi-channel controllers are based on microprocessors, programmable logic controllers, and microcomputers, and can be applied to any system and network. The following are some typical system building schemes.

l 4-20mA

The sensor directly feeds the 4-20mA signal directly to the multi-channel controller. The controller repeatedly displays these signals and also provides backup relays and RS-485 outputs.

l 4-20mA plus local relay

The 4-20mA signal directly fed back to the multi-channel controller triggers an alarm or other response device along with the output signal from the relay. The controller also provides backup relays and RS-485 outputs.

l RS-485 communication plus local relay

The sensors are connected via the RS-485 communication bus to trigger alarms or other reaction equipment together with the output signal of the relay. The programmable logic controller provides all data processing, display and historical records.

l 4-20mA plus RS-485 communication bus

The 4-20mA signal of the sensor is imported into the DA-1 data module to be converted into a signal that can be processed by RS-485. The DA-1 data module feeds data back to the Model 880 programmable logic controller. The controller provides all data processing, display and historical records. The programmable logic controller can be further connected to the computer through the human-machine communication interface through Citect, Wonderware or other software.

Imported original amp type electrochemical sensor, usually composed of three electrodes immersed in the electrolyte. The working electrode is made of a catalytically active metal and coated on a breathable but hydrophobic membrane. The measured gas diffuses through the porous membrane and undergoes an electrochemical oxidation or reduction reaction thereon. The nature of the reaction depends on the thermodynamic potential of the working electrode and the electrochemical (oxidation or reduction) properties of the analysis gas. In the electrochemical reaction, the electrons participating in the reaction flow in (reduction) or flow out (oxidize) the working electrode. The working signal of the working electrode is amplified by the operational amplifier U2 to become the output signal of the instrument. The circuit also maintains the voltage of the working electrode to the value of its bias VBIAS. The reference electrode provides a stable potential for the working electrode in the electrolyte. After the reference electrode potential is compared with VBIAS, the output voltage signal is output at op amp U1, and its magnitude is exactly the same as that of the working electrode. At the same time, the circuit maintains a constant potential difference between the working electrode and the reference electrode. The measuring electrode is only the second electrode required for a complete electrochemical sensor, and its main function is to allow electrons to enter or flow out of the electrolyte.

The gas release source is located in the equipment area arranged in the open air or semi-open air. The distance between the detection point and the release source should meet the following requirements:

1. When the detection point is located on the upwind side of the minimum frequency wind direction of the release source, the distance between the hydrogen sulfide detection probe and the release source should not be greater than 2m.

2. When the detection (probing) measurement point is located on the downwind side of the minimum frequency wind direction of the release source, the distance between the hydrogen sulfide detection probe and the release source should be less than 1m.

The toxic gas release source is located in a closed or semi-closed workshop, and the hydrogen sulfide detection probe should not be more than 1m away from the release source.

Mainly used in coal mine, metallurgy, chemical industry, liquefied gas station and other industries to detect harmful gas concentrations and other harmful gases in the working environment.

Features

& laquo; Fast response time

& laquo; Simple operation and stable performance

& laquo; LCD display, direct reading

& laquo; Reliable performance without frequent maintenance

& laquo; Sound and light alarm, easy calibration

& laquo; Small size and easy to carry

& laquo; Separate meter and probe, can be detected online, instant reading (fixed)

1 Physical and chemical properties

It is a colorless gas. Has a smell of rotten eggs. Molecular formula H2-S. The molecular weight is 34.08. The relative density is 1.19. Melting point: -82.9 ° C. Boiling point is -61.8 ° C. Soluble in water, but also in alcohols, petroleum solvents and crude oil. The flammable upper limit is 45.5% and the lower limit is 4.3%. The ignition point is 292 ° C.

2 opportunities

In mining and refining copper, nickel, cobalt, etc., low-temperature coking of coal, mining and refining of sulfur-containing oil, rubber, rayon, tanning leather, sulfur dyes, papermaking, pigments, vegetable pickling, sugar beet, animals Hydrogen sulfide is produced in industries such as rubber; excavation and remediation of marshes, ditches, wells, sewers, culverts, tunnels, and removal of garbage, dirt, feces and other operations; and analytical chemical laboratory workers are exposed to hydrogen sulfide Natural gas, mineral water, volcanic jets and stagnant water under the mine are often accompanied by the presence of hydrogen sulfide. Because hydrogen sulfide is soluble in water and oil, it can sometimes flow with water or oil away from the source, causing accidental poisoning.

Technical parameters of hydrogen sulfide gas transmitter Static working parameters: 3 mA @ 10.5 45 VDC Working voltage: 24VDC (10.5 45 VDC) Analog signal output: 4 22.8 mA linear current output; 3.6 mA fault current output digital signal output: Response time without standard HART protocol T90: Less than 15 seconds Recovery time: less than 30 seconds Resolution: 1 uA Accuracy: ± 3% FS; ± 1% FS (custom) Display mode: LCD LCD display with backlight Content: 5 digits Display value indication, 8-digit meter-shaped information prompt, 50-segment percentage bar prompt prompt Setting unit: ppm,% VOL, mA,% Working environment temperature: -40 to 70 ° C (specifically according to sensor parameters) Working environment humidity: 10- 95% RH (non-condensing) Explosion-proof grade: Ex d IIC T6 (Explosion-proof application); Ex ia IIC T4 (Intrinsically safe application) Housing material: Aluminum explosion-proof enclosure Other accessories: Stainless steel Overall size: 160mm (L) 140mm (W) 85mm (H) Degree of protection: IP66 Weight of whole machine: Approx. 1.5 kg