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PT295 Series Combustible Gas Sensor
Features
- Microprocessor based modular design
- Electrochemical Sensor Technology
- Industry standard 4-20mA output
- Field adjustable Alarm level
- Single point Non-Intrusive calibration
- Bright 3 digit LED display
- Displays oxygen concentration, calibration prompts and sensor fault codes
- Class I, Div 1, Suitable for use in Hazardous Location
Description
Model PT295-LEL is a microprocessor-based sensor designed to combustible hydrocarbons in % volume level. The unit features easy one-man calibration initiated by simply activating a magnetic switch and applying the gas.
The complete sensor consists of a stainless steel sensor head assembly, a user connection board and a transmitter board assembly. All of the sensor electronics are enclosed in an explosion proof instrument box. The unit’s modular design allows easy maintenance, troubleshooting and high reliability.
The unit provides a 4-20mA signal proportional to 0 to 100% of the detection range of the sensor and a fully programmable alarm relay.
The sensor transmitter board includes a three (3) digit LED display for continuous indication of the gas concentration. The calibration mode, alarm and fault status of the sensor are also indicated on the digital display. In the normal operating mode the digital display and 4-20mA reading is proportional to the gas concentration detected by the sensor. In the calibration mode the digital display indicates the calibration status, alarm relay output is inhibited and analog signal output is set to 2 mA to avoid any false alarm by the control monitor. In the sensor fault mode the transmitter drops the output signal to < 1 mA.
Specifications
- Sensor Type
- Continuous diffusion Catalytic Bead
- Measuring Range
- 0 to 100% LEL
- Repeatability
- ± 2 % Full scale
- Zero Drift
- < 5% per year
- Response Time
- T50 < 10 seconds
- T90 < 30 seconds
- with 100% LEL methane gas applied
- Classification
- Class I, division 1, Groups B,C & D
- Operating Temperature
- -40°F to +158°F (-40°C to +70°C)
- Operating Humidity
- 10% to 90% RH, non-condensing
- Mechanical Specifications
- Length: 7 inches (178 mm)
- Width: 5 inches (127 mm)
- Height: 4.5 inches (114 mm)
- Display
- Bright 3 digit LED display
- Status Indicators
- Three-digit display for gas concentration
- Alarm relay status, calibration mode and
- sensor fault status.
- Approvals
- ABS Type approved
- ATEX / CSA approved for use in
- hazardous locations.
- CSA Performance test: ISA-S12.13-
- Part I-1995
- Input Power
- 14-28 VDC. 24 VDC nominal
- Power Consumption
- 150mA @ 24 VDC Typical
- Alarm Relays
- Fully programmable.
0 to Full scale range of the sensor.
Latching or Non-Latching.
- Fully programmable.
- Relay Ratings
- SPDT Form “C” type Relay contacts
- 5 Amps @ 250 VAC or 30 VDC
- Analog Output
- Linear 4-20mA (300 Ohms max. load)
- 2.0 mA - Calibration mode
- < 1.0 mA - Sensor malfunction
- Calibration
- Non-Intrusive activated
by internal magnetic switch
- Non-Intrusive activated
- Cable Requirement
- 3 wire shielded cable. Max loop
resistance 20 Ohms
- 3 wire shielded cable. Max loop
- Cable Entry Hub
- ¾” NPT Female


