Product Overview

The VQ500 Series is a range of miniature, fully certified, flameproof catalytic combustible gas sensor heads. Optimized for low power consumption and featuring a pellistor pair, these sensors are designed for detecting 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. The sensors are designed with an outline identical to modern miniature electrochemical cells, making them ideal for use in portable instruments. They are poison-resistant to silicones and hydrogen sulfide, shock-resistant, and available in ATEX, IECEx, CSA, and UL certified variants. Specific models are temperature rated between -40C and +55C, with some variants undergoing routine temperature testing for mining performance standards compliance.

Product Attributes

• Brand: SGX
• Product Line: VQ500 Series
• Certifications: ATEX, IECEx, CSA, UL
• Body Material: Stainless Steel
• Poison Resistance: Silicones and Hydrogen Sulfide
• Certifications: ATEX (II 2G Ex db IIC Gb, I M2 Ex db I Mb), IECEx (Ex db IIC Gb, Ex db I Mb), CSA (Component certification for Explosion Proof Enclosure, Class I hazardous locations), UL (Component recognition for intrinsically safe apparatus, Class 1, Division 1, Groups A, B, C, D)

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	Outline
VQ546M	4.25 0.1	50 60	-	-4.0 (1% Methane) 15	Not Required	No	No	A
VQ546MR	4.25 0.1	50 60	-	+4.0 (1% Methane) 15	Not Required	No	No	A
VQ547TS	3.0 0.1	40 50	21 (1.5% Ammonia)	30	Some	No	No	A
VQ548ZD	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	No	No	B
VQ548ZD/W	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	Yes	No	B
VQ548ZD-S	3.0 0.1	67 80	20 (1% Methane)	20	Silicones & H2S	No	Yes	B
VQ549ZD	4.25 0.1	50 60	30 (1% Methane)	20	Silicones & H2S	No	No	B
VQ549ZD/W	4.25 0.1	50 60	30 (1% Methane)	20	Silicones & H2S	Yes	No	B
Environmental
Temperature range for operation and storage		40 to +55 C
Humidity range for operation and storage		0 to 80% (non-condensing)
Electrical
Supply Voltage		3.00 V to 4.25 V (Depending upon type)
Supply Power		135 mW to 230 mW (Depending upon type)
Performance
Linearity (Catalytic)		Linear up 60%LEL
Linearity (Thermal Conductivity)		Refer to Pellistor Application Note 5
Response Time (T90)		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
VQ546M, VQ546MR	100%v/v
VQ547TS, VQ548, VQ549	100%LEL
Mechanical
Weight		22g

2404071846_Amphenol-VQ548ZD-W_C3659409.pdf