51 Series

Explosion-proof Gas Analyzer

The 51 Series comprises rugged, explosion-proof gas analyzers tailored for flammable or classified locations. Certified to major safety standards, these units use infrared, thermal conductivity, magneto-pneumatic, or paramagnetic methods to measure CO, CO₂, CH₄, H₂, O₂, and other gases with uncompromised safety and accuracy.

51 Series

Explosion-proof Gas Analyzer

Why Choose 51 Series

Intrinsic Safety – Certified for explosive atmospheres (JPEx/IEC 60079), ensuring safe operations within hazardous zones.
Robust, Real-Time Monitoring – Delivers continuous gas measurements across a wide concentration range, resisting external interference.
Smart Reliability – Features self-diagnosis and interference correction to maintain precision and alert users to anomalies.
Operator-Friendly Interface – Bright LED display provides easy, at-a-glance status updates even in challenging environments.

Key Advantages of 51 Series

Certified for Hazardous Areas

Explosion-Proof Design

Engineered to operate safely in zones with flammable gases and hazardous atmospheres.

Wide Gas & Range Coverage

CO, CO₂, CH₄, H₂, O₂

Supports multiple gas detection methods for a variety of industrial needs.

Diagnostic & Calibration Support

Self-Diagnosis + Correction

Automatically detects faults and compensates for interference to maintain reliable output.

High-Visibility Interface

LED Display

Offers clear operational feedback in low-light or demanding conditions for improved usability.

Technical Specifications of 51 Series

Model			EIA-51d	EIA-51p	TIA-51d	TIA-51p
Type of protection			Exd Ⅱ B+H₂T4	Expx Ⅱ T4X	Exd Ⅱ B+H₂T4	Expx Ⅱ T4X
Frameproof enclosures			●		●
Pressurized apparatus				●		●
Measuring principle			Non-Dispersive Infrared Absorption Method (NDIR)
Component			CO, CO₂, CH₄, etc.^*1
Measurement range	Minimum range		0 to 0.11 vol% (Depends on the component)		0 to 50 ppm (Depends on the component)
	Maximal range		0 to 100 vol% (Depends on the component)		0 to 2000 ppm (Depends on the component)
	Optional		100-90 to 50 vol% (Depends on the component)		0-20 to within less than 50 ppm (Depends on the component)	—
Range Ratio			—		—
Performance	Repeatability	Standard range	Zero : ±0.5% of full scale		Zero : ±0.5% of full scale
		Standard range	Span : ±0.5% of full scale		Span : ±0.5% of full scale
		Optional range	Zero : ±0.5% of full scale		Zero : ±1.0% of full scale
		Optional range	Span : ±0.5% of full scale		Span : ±1.0% of full scale
	Linearity		±1.0% of full scale
	Drift^*2	Standard range	Zero : ±2.0% of full scale/week
		Standard range	Span : ±2.0% of full scale/week
		Optional range	Varies by specification
		Optional range	Varies by specification
	Response time (from inlet of analyzer)		—		T₉₀ within 20 seconds T₉₀ within 40 seconds (TIA optional range)
Sample gas Condition	Gas composition	Flameproof enclosures	O₂ : 21% or less, no mist, no dust The hazardous must be equivalent or less with electrical apparatus group Ⅱ B, gas and vapor-air mixture corresponding to temperature code T4, and Hydrogen-air mixture.
	Gas composition	Pressurized apparatus	O₂ : 21% or less, no mist, no dust The ignition temperature must be equivalent or less with electrical apparatus of gas and vapor-air mixture corresponding to temperature code T4.
	Pressure		Over 1.98 kPa
	Flow rate		Approx. 500 mL/min.
	Temperature		Ambient temperature
	Exhaust		Atmosphere pressure
Materials in contract with sample gas			SUS304, SUS316, FKM, CaF₂, Au, etc.
Calibration method			Standard : Manual correction, Option : Automatic correction
Analog output	Output content / Output specifications		1 concentration output channel / DC 4 to 20 mA (DC 0 to 16 mA / 0 to 20 mA, DC 0 to 1 V / 0 to 5 V / 1 to 5 V / 0 to 10 V optional)
Analog output	Alarm setting		Arbitrary setting is available with span range from -10% to +110% of output for current and voltage. Negative output values set to zero.
Contact Input-output (option)			6 channels
Digital connection (option)	Interface		RS-485
	Protocol		Modbus-RTU
	Communication speed		Selected from 19200 bps / 9600 bps / 4800 bps / 2400 bps / 1200 bps
Environment conditions	Location		Indoors
	Operational Temperature		-5 to 40 °C (away from direct sunlight and radiant heat)
	Humidity		90% or less
	Vibration		Avoid large vibration sources (less than 100 Hz; 0.3 m/s²)
Utility	Protective gas for Pressurized apparatus composition		Gas composition : N₂, Gas pressure : 196 to 690 kPa, Gas flow rate : 10 L/min. (when purging), 500 mL/min. (when operating) Dew Point : -30°C Saturated or less