Product Overview

The VQ500 Series is a range of miniature, fully certified, flameproof catalytic combustible gas sensor heads. Optimized for low power consumption, these sensors utilize a pellistor pair for detecting combustible gases and % volume gases in thermal conductivity mode. With an outline identical to modern miniature electrochemical cells, they are ideal for portable instruments. The series offers sensors capable of detecting most combustible gases and vapors, as well as ammonia at LEL levels. Thermal conductivity versions can detect gases with thermal conductivities different from air at % volume concentrations. Specific variants undergo temperature testing for mining performance standards and enhanced stability through burn-in.

Product Attributes

• Brand: SGX
• Product Line: VQ500 Series
• Certifications: ATEX, IECEx, CSA, UL Recognized
• Material (Enclosure): Stainless Steel
• Material (Mesh): Stainless Steel
• Material (Bushing): Epoxy resin
• Poison Resistance: Silicones and Hydrogen Sulfide
• Shock Resistant: Yes (specific variants)
• Explosion Proof Component: Yes
• Integral Pellistors: Yes
• Low Power: Yes
• Standard Miniature Body Size: Yes

Technical Specifications

Model	Operating Voltage (V d.c)	Sensor Current (mA)	Minimum Sensitivity (mV/%Vol)	Offset (mV)	Routine Temperature Tested	Routine Burn-In and Drift Test	Outline
VQ546M	4.25 0.1	50 60	- (1% Methane)	15	No	No	A
VQ546MR	4.25 0.1	50 60	+4.0 (1% Methane)	15	No	No	A
VQ547TS	3.0 0.1	40 50	21 (1.5% Ammonia)	30	Some	No	A
VQ548ZD	3.0 0.1	67 80	20 (1% Methane)	20	No	No	B
VQ548ZD/W	3.0 0.1	67 80	20 (1% Methane)	20	Yes	No	B
VQ548ZD-S	3.0 0.1	67 80	20 (1% Methane)	20	No	Yes	B
VQ549ZD	4.25 0.1	50 60	30 (1% Methane)	20	No	No	B
VQ549ZD/W	4.25 0.1	50 60	30 (1% Methane)	20	Yes	No	B
Mechanical Dimensions: See outline, page 3
Weight: 22g
Environmental Temperature range for operation and storage: 40 to +55 C
Humidity range for operation and storage: 0 to 80% (non-condensing)
Supply Voltage: 3.00 V to 4.25 V (Depending upon type)
Supply Power: 135 mW to 230 mW (Depending upon type)
Operating Temperature Range: -40C and +55C
Maximum Gas Concentrations: VQ546M, VQ546MR: 100%v/v; VQ547TS, VQ548, VQ549: 100%LEL
Warranty Period: 12 months
Product Marking: ATEX: II 2G Ex db IIC Gb I M2 Ex db I Mb; IECEx: Ex db IIC Gb Ex db I Mb Ta -40C to +55C, Pi: 2.5 W
Hazardous Area Installation Note: Maximum output (Po) not greater than 2.5 W for intrinsically safe supply. Maximum temperature rise on external surface does not exceed 64 C.