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 in thermal conductivity mode for detecting combustible gases and % volume gases. Their standard miniature electrochemical cell outline makes them ideal for portable instruments. The series offers sensors capable of detecting most combustible gases, vapors, and ammonia at LEL levels, as well as 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
• Certifications: ATEX, IECEx, CSA, UL Recognized
• Material: Stainless Steel (Enclosure), Stainless Steel (Mesh), Epoxy Resin (Bushing)
• Poison Resistance: Silicones and Hydrogen Sulfide
• Features: Certified explosion proof component, Integral pellistors, Low power, Standard miniature body size, Shock resistant

Technical Specifications

Specification	Details
Product Series	VQ500 Series
Sensor Type	Catalytic Combustible Gas Sensor (4-Series)
Operating Principle	Pellistor pair in thermal conductivity mode
Mechanical Dimensions	See outline, page 3
Body Material	Stainless Steel
Weight	22g
Environmental Temperature Range (Operation & Storage)	-40 to +55 C
Environmental Humidity Range (Operation & Storage)	0 to 80% (non-condensing)
Electrical Supply Voltage	3.00 V to 4.25 V (Depending upon type)
Electrical Supply Power	135 mW to 230 mW (Depending upon type)
Performance: Linearity	Catalytic: Linear up 60%LEL; Thermal Conductivity: Refer to Pellistor Application Note 5
Performance: Response Time (T90)	< 20 seconds
Performance: Long Term Zero Drift (ZD-S Variants)	<5%LEL / month (based upon a 1 month period)
Performance: Long Term Zero Drift (All other Types)	<5%LEL / month (based upon a 12 month period)
Performance: Long Term Sensitivity Drift (ZD-S Variants)	<5% Full-Scale / month (based upon a 1 month period)
Performance: Long Term Sensitivity Drift (All other Types)	<5% Full-Scale / month (based upon a 12 month period)
Performance: Zero Offset with Temperature (ZD/W Variant Only)	≤ 0.2% methane variation between -10C to +40C (compared to 20C reading)
Warranty Period	12 months
Maximum Gas Concentrations (Note d) VQ546M, VQ546MR	100%v/v
Maximum Gas Concentrations (Note d) VQ547TS, VQ548, VQ549	100%LEL
Product Variants	VQ546M, VQ546MR, VQ547TS, VQ548ZD, VQ548ZD/W, VQ548ZD-S, VQ549ZD, VQ549ZD/W
Product Variants: VQ546M Operating Voltage	4.25 ±0.1 V d.c.
Product Variants: VQ546M Sensor Current	50 60 mA
Product Variants: VQ546M Minimum Sensitivity	-4.0 mV (1% Methane) ±15
Product Variants: VQ546MR Minimum Sensitivity	+4.0 mV (1% Methane) ±15
Product Variants: VQ547TS Operating Voltage	3.0 ±0.1 V d.c.
Product Variants: VQ547TS Sensor Current	40 50 mA
Product Variants: VQ547TS Minimum Sensitivity	21 mV (1.5% Ammonia) ±30
Product Variants: VQ548ZD Operating Voltage	3.0 ±0.1 V d.c.
Product Variants: VQ548ZD Sensor Current	67 80 mA
Product Variants: VQ548ZD Minimum Sensitivity	20 mV (1% Methane) ±20
Product Variants: VQ548ZD/W Routine Temperature Tested	Yes
Product Variants: VQ548ZD-S Routine Burn-In and Drift Test	Yes
Product Variants: VQ549ZD Operating Voltage	4.25 ±0.1 V d.c.
Product Variants: VQ549ZD Sensor Current	50 60 mA
Product Variants: VQ549ZD Minimum Sensitivity	30 mV (1% Methane) ±20
Product Variants: VQ549ZD/W Routine Temperature Tested	Yes
Hazardous Area Installation: Max Output (Po)	2.5 W
Hazardous Area Installation: Max Temperature Rise	64 C
Hazardous Area Installation: Ambient Temperature Range	-40C and +55C