Gas detector, Gas sensor,as measuring, For measuring explosive and toxic gases and vapours.
MF 420 Gas sensor , Gas detector, Design of the gas measuring system
The sensor sits in an approx. 46 mm long stainless steel probe tube. Cable entry is by means of a screwed cable gland (clamping area 6-10mm).The aluminium hosing incorporates: a four-digit, alphanumeric display, two buttons and the transmitter with a signal amplifier and a 4-20mA analog output . The transmitter processes and transmits the measured signals. It functions according to the three-wire system.
Principle of operation
The MF420-Ex-2 (Pellistor) gas measuring system determines the concentration of flammable gases and vapours in an explosive air mixture at an ambient temperature of -20 centigrade to +40 centigrade (optionally from -40 to +60centigrade). It is certified for use in areas subject to explosion hazards and has an EC Type Examination Certificate in accordance with Directive 94/9/EC (ATEX 100a) as follows:
TPS 09 ATEX 1 421 X
EX II 2G Ex dIICT6
Transmitter |
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Power supply | Cage clamp | 0.5-2.5mm2 |
| Voltage | 24V DC ± 5% |
| Current | Approx. 105mA at 24V |
Connections | Pin(-) | 0V |
| Pin(S) | 4-20mA ;max. Load 500 ohms |
| Pin(+) | 24 V DC ± 5% |
Ambient temperature | -20 centigrade to 40 centigrade | Temperature range -40 centigrade to +60 on request |
Air pressure | 700 hPa to 1300 hPa |
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Permissible humidity | 10-95% relative humidity | Non-condensing |
Output | 4-20mA |
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Hosing | Aluminium alloy/stainless steel | Silver |
Protection class of housing | IP 65 | Saltwater-proof |
Hosing weight | Approx. 1,100 g |
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Housing dimensions | Approx. 84*H78mm | Without probe tube and Screwed connection |
Connection cable | 3*1.5mm2Cu+functional ground | Shielded cable |
Display | Four-digit alphanumeric display | Displays measured value and/or staus |
Controls | 2 buttons |
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Certification |
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EC Type Examination Certificate | TPS 09 ATEX 1 421 X EX II 2G Ex dIIC T6 | In accordance with Dirctive 94/9/EC (ATEX100a) |
Sensor |
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Sensor type | Pellistor |
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Gas access | By diffusion |
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Measuring range | 0-100% LEL |
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Warm-up time | Approx. 5 min |
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