ST8990 Industrial 4-Gas Portable Detector – CO / H₂S / O₂ / LEL, IP65 Explosion-Proof Gas Analyzer

Product Overview

The ST8990 Industrial Portable 4-Gas Detector is a professional-grade safety instrument designed for continuous monitoring of Carbon Monoxide (CO), Hydrogen Sulfide (H₂S), Oxygen (O₂), and Combustible Gas (LEL) in hazardous environments.

Equipped with electrochemical sensors, the ST8990 delivers fast response, high accuracy, and stable performance. When gas concentrations exceed preset safety thresholds, the device immediately triggers audible, visual, and vibration alarms, ensuring timely warnings for personnel safety.

Its rugged ABS housing, IP65 protection, and explosion-proof design make it suitable for demanding industrial applications such as confined spaces, pipelines, mines, tunnels, and chemical plants.

Key Features

• 4-Gas Detection in One Device
  Simultaneously monitors CO, H₂S, O₂, and LEL.

• Real-Time Continuous Monitoring
  Displays live gas concentration levels on a large color LCD.

• Triple Alarm System
  Audible (up to 80dB), visual, and vibration alarms when limits are exceeded.

• Adjustable Alarm Thresholds
  User-configurable low and high alarm values.

• Fast Response & Short Warm-Up
  Ready for operation in less than 20 seconds.

• Sampling Pump Compatible
  Can be connected to an external pump for confined or enclosed spaces.

• Industrial-Grade Protection
  IP65 rated, explosion-proof, suitable for harsh environments.

• Portable & Rechargeable
  Built-in 2500mAh lithium battery, up to 6 hours continuous operation.

Typical Applications

• Oil & gas industry

• Chemical plants

• Mining and tunneling

• Firefighting and emergency rescue

• Gas pipelines and utilities

• Municipal and industrial maintenance

• Confined space inspection

Technical Specifications

Model: ST8990
Brand: SMART SENSOR
Material: ABS Plastic
Color: Orange
Display: Color LCD with backlight
Display Size: 47 × 38 mm (1.9 × 1.5 in)

Detected Gases:

• Carbon Monoxide (CO)

• Hydrogen Sulfide (H₂S)

• Oxygen (O₂)

• Combustible Gas (LEL)

Measurement Range:

• CO: 0–999 ppm

• H₂S: 0–500 ppm

• O₂: 0–30% VOL

• LEL: 0–100% LEL

Resolution:

• CO: 1 ppm

• H₂S: 1 ppm

• O₂: 0.1% VOL

• LEL: 1% LEL

Accuracy:

• CO: ±10%

• H₂S: ±5%

• O₂: ±3% FS

• LEL: ±5% FS

Alarm Settings:

• Low Alarm:
  CO 35ppm | H₂S 10ppm | O₂ 19.5%VOL | LEL 10%LEL

• High Alarm:
  CO 70ppm | H₂S 20ppm | O₂ 22.5%VOL | LEL 20%LEL

Alarm Type: Sound / Light / Vibration
Alarm Volume: Up to 80dB

Warm-Up Time: < 20 seconds
Response Time: Instantaneous

Power Supply:
Built-in rechargeable lithium battery (3.7V, 2500mAh)

Continuous Working Time:
Approx. 6 hours (depending on conditions)

Protection Grade: IP65
Explosion Proof: Yes

Operating Temperature: -10°C to 50°C (14°F to 122°F)
Operating Humidity: 15%–95% RH (non-condensing)

Product Size: 140 × 75 × 43 mm
Product Weight: Approx. 249 g

Package Includes

• 1 × ST8990 4-Gas Detector

• 1 × USB Charging Cable

• 1 × Protective Storage Case

• 1 × User Manual (English)

Click here to download the manual.