| Operating Principle | Catalytic oxidation on a heated pellistor bead, detected as a resistance change. A second inert bead compensates for ambient temperature variations. |
| Mechanical Dimensions | Refer to outline drawing (Page 3) |
| Body Material | Stainless Steel |
| Weight | 22g |
| Environmental Operating & Storage Temperature Range | -40 to +55 C |
| Environmental Humidity Range (non-condensing) | 0 to 80% |
| 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 to 60%LEL; Thermal Conductivity: Refer to Pellistor Application Note 5 |
| Response Time (T90) | < 20 seconds |
| Long Term Zero Drift (ZD-S Variants) | <5%LEL / month (1 month period) |
| Long Term Zero Drift (All other Types) | <5%LEL / month (12 month period) |
| Long Term Sensitivity Drift (ZD-S Variants) | <5% Full-Scale / month (1 month period) |
| Long Term Sensitivity Drift (All other Types) | <5% Full-Scale / month (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; VQ547TS, VQ548, VQ549: 100%LEL |
| Product Variants | | Model | Operating Voltage (V d.c) | Sensor Current (mA) | Minimum Sensitivity (mV/%Vol) | Offset (mV) | Poison Resistance | Outline | Routine Temp Tested | Routine Burn-In & Drift Test | | VQ546M | 4.25 0.1 | 50 60 | -4.0 (1% Methane) | 15 | Not Required | A | No | No | | VQ546MR | 4.25 0.1 | 50 60 | +4.0 (1% Methane) | 15 | Not Required | A | No | No | | VQ547TS | 3.0 0.1 | 40 50 | 21 (1.5% Ammonia) | 30 | Some | A | No | No | | VQ548ZD | 3.0 0.1 | 67 80 | 20 (1% Methane) | 20 | Silicones & H2S | B | No | No | | VQ548ZD/W | 3.0 0.1 | 67 80 | 20 (1% Methane) | 20 | Silicones & H2S | B | Yes | No | | VQ548ZD-S | 3.0 0.1 | 67 80 | 20 (1% Methane) | 20 | Silicones & H2S | B | No | Yes | | VQ549ZD | 4.25 0.1 | 50 60 | 30 (1% Methane) | 20 | Silicones & H2S | B | No | No | | VQ549ZD/W | 4.25 0.1 | 50 60 | 30 (1% Methane) | 20 | Silicones & H2S | B | Yes | No | |
| Certifications Details | - ATEX: II 2G Ex db IIC Gb I M2 Ex db I Mb Ta -40C to +55C, Pi: 2.5 W (EC Type-Examination Certificate: Sira 01ATEX1073U)
- IECEx: Ex db IIC Gb Ex db I Mb Ta -40C to +55C, Pi: 2.5 W (IECEx Certificate: IECEx SIR 04.0014U)
- CSA: Component certification for Explosion Proof Enclosure, Class I hazardous locations (Standard C22.2 No. 30-M 1986, Certificate No. 2589677). Assessed to UL 1203 (4th Edition).
- UL: Component recognition for intrinsically safe apparatus, Class 1, Division 1, Groups A, B, C, D hazardous locations (UL 913, 7th edition, File E186043).
|
| Hazardous Area Installation Instructions | - Component approved only; requires further protection for standalone use in hazardous areas.
- Must be used with an intrinsically safe supply (max output Po 2.5 W).
- Maximum temperature rise on external surface does not exceed 64 C.
- For Group I applications, must withstand impact energy > 7 J.
- Not assessed as a safety device.
- No user-serviceable parts.
- Certification relies on Stainless steel enclosure/mesh and Epoxy resin bushing.
- Shall only be used in an ambient temperature range of -40C to +55C.
|