Name: HQT-1000 Series Fixed Gas Detector
Brand: Huanqitong
SKU: HQT-1000
Availability: InStock

Overview

Fixed gas detectors are installed at process units, tank farms, fence lines and utility tunnels where 24/7 continuous online monitoring is required. They measure combustible gas, toxic gas and oxygen concentrations in real time and transmit 4-20mA or RS485 / Modbus signals to a DCS, PLC or gas alarm controller for audible/visual alarms, fan activation and valve shutdown.

Any combination from 2-in-1 to 7-in-1 is available, with electrochemical, catalytic bead, PID and NDIR sensors selected per application. Measuring ranges and alarm thresholds are customizable.

Typical Specifications

Target Gases

Combustible (LEL), O2, CO, H2S, NH3, Cl2, SO2, NO2, VOC — 2-in-1 to 7-in-1 combinations.

Detection Principle

Catalytic bead / electrochemical / PID / NDIR, matched to the target gas.

Output Signal

4-20mA, RS485 / Modbus RTU, relay output; optional 4G / LoRa wireless.

Explosion & Protection

Ex d IIC T6 design, IP66 rated for outdoor and corrosive environments.

Operating Temperature

-20°C to +50°C (high-temperature versions above 200°C with sampling preconditioning).

Power Supply

24 VDC standard, wide-voltage design available.

Installation & Selection Notes

Mounting height: heavier-than-air gases (H2S, SO2, Cl2, LPG) at 0.3–0.6 m above floor; lighter-than-air gases (methane, hydrogen, ammonia) 0.5–2 m above the leak source; oxygen detectors at about 1.5 m.

Point layout: place detectors by leak source distribution, ventilation and worker zones — typically one point every 15–20 m in process areas, covering valves, flanges and pump seals.

Recommended pairing: fixed detectors cover the area; pair with portable gas detectors for patrol checks, and manage the system through a gas alarm controller.

Selectable Gases & Models

HQT series · ranges & combinations customizable

Model	Gas	Typical Range	Principle
HQT-1000-CH4	Methane / Combustible	0-100%LEL	Catalytic bead
HQT-1000-H2S	Hydrogen sulfide	0-100 ppm	Electrochemical
HQT-1000-CO	Carbon monoxide	0-1000 ppm	Electrochemical
HQT-1000-O2	Oxygen	0-30%VOL	Electrochemical
HQT-1000-NH3	Ammonia	0-100 ppm	Electrochemical
HQT-1000-Cl2	Chlorine	0-20 ppm	Electrochemical
HQT-1000-SO2	Sulfur dioxide	0-20 ppm	Electrochemical
HQT-1000-VOC	VOC	0-200 ppm	PID
HQT-1000-HF	Hydrogen fluoride	0-10 ppm	Electrochemical
HQT-1000-SO2F2	Sulfuryl fluoride	0-50 ppm	Electrochemical
HQT-1000-4S	4-in-1 LEL/O2/CO/H2S	—	Composite

FAQ

How often should fixed detectors be calibrated?

Every 6-12 months recommended, depending on conditions, gas type and environment; shorter for toxic or corrosive gases.

Which gas combinations are supported?

2-in-1 to 7-in-1 covering LEL, O₂, CO, H₂S, NH₃, Cl₂, SO₂, NO₂, VOC etc., with catalytic bead, electrochemical, PID and NDIR sensors per application.

What output signals are available?

Standard 4-20mA and RS485 / Modbus RTU, optional relay and 4G / LoRa wireless, connecting to DCS, PLC or gas alarm controllers.

Can it be customized?

Yes. Range, alarm thresholds, housing material, output protocol and mounting are all OEM / ODM customizable.

HQT-1000 SeriesFixed Gas Detectors