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 the detection of combustible gases and vapors, as well as ammonia, at LEL levels. Thermal conductivity versions are also available for detecting gases with thermal conductivities different from air at % volume concentrations. Designed with an outline identical to modern miniature electrochemical cells, they are ideal for portable instruments. The series offers poison resistance to silicones and hydrogen sulfide, shock resistance, and is certified for hazardous environments including ATEX, IECEx, CSA, and UL recognized.

Product Attributes

• Brand: SGX Sensortech
• Product Line: VQ500 Series
• Sensor Type: Catalytic Combustible Gas Sensor (4-Series)
• Certifications: ATEX, IECEx, CSA, UL Recognized
• Body Material: Stainless Steel
• Poison Resistance: Silicones and Hydrogen Sulfide
• Operating Temperature Range: -40C to +55C
• Origin: Poland (SGX Europe Sp. z o.o.)

Technical Specifications

Model	Operating Voltage (V d.c)	Sensor Current (mA)	Minimum Sensitivity (mV/%Vol)	Offset (mV)	Poison Resistance	Routine Temperature Tested	Routine Burn-In and Drift Test
VQ546M	4.25 0.1	50 60	- (1% Methane)	15	Not Required	No	No
VQ546MR	4.25 0.1	50 60	+4.0 (1% Methane)	15	Not Required	No	No
VQ547TS	3.0 0.1	40 50	21 (1.5% Ammonia)	30	Some	No	No
VQ548ZD	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	No	No
VQ548ZD/W	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	Yes	No
VQ548ZD-S	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	No	Yes
VQ549ZD	4.25 0.1	50 60	30 (1% Methane)	20	Silicones & H2S	No	No
VQ549ZD/W	4.25 0.1	50 60	30 (1% Methane)	20	Silicones & H2S	Yes	No

Specification	Value
Mechanical Dimensions	See outline, page 3
Weight	22g
Environmental Humidity Range (Operation & 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)
Linearity (Catalytic Thermal Conductivity)	Linear up 60%LEL
Response Time (T90)	< 20 seconds
Long Term Zero Drift (ZD-S Variants)	<5%LEL / month (based upon a 1 month period)
Long Term Zero Drift (All other Types)	<5%LEL / month (based upon a 12 month period)
Long Term Sensitivity Drift (ZD-S Variants)	<5%Full-Scale / month (based upon a 1 month period)
Long Term Sensitivity Drift (All other Types)	<5% Full-Scale / month (based upon a 12 month period)
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 Marking (ATEX)	II 2G Ex db IIC Gb I M2 Ex db I Mb Ta -40C to +55C, Pi: 2.5 W
Product Marking (IECEx)	Ex db IIC Gb Ex db I Mb Ta -40C to +55C, Pi: 2.5 W
CSA Certificate No.	2589677
UL File No.	E186043
Maximum External Surface Temperature Rise	Does not exceed 64 C
Enclosure Material	Stainless steel
Mesh Material	Stainless steel
Bushing Material	Epoxy resin