DISCOVERY, CO/HEAT MULTISENSOR DETECTOR 58000-305
 | DISCOVERY CO/HEAT MULTISENSOR DETECTOR |
Operating Principles
The Discovery CO/Heat Multisensor Detector contains a CO detection cell and a thermistor temperature sensor whose outputs are combined to give the final analogue value. The way in which the signals from the two sensors is combined depends on the response mode selected. The CO/ Heat Multisensor detects the presence of carbon monoxide or heat or a combination of both.
The Multisensor construction is similar to that of a CO detector but uses a different lid in order to expose the thermistor to the surrounding air.
The signals from the CO sensing cell and the thermistor are independent and represent the amount of CO or the temperature present in the vicinity of the detector.
When the detector is used in heat only mode (Mode 5) it operates as an A1R rate-of-rise heat detector with a static threshold of 58ºC
Additional Heat Sensor Information
Discovery CO/Heat Multisensor detectors incorporate additional temperature information that is intended for use in signal processing. This is done in the same way as for the Optical/Heat Multisensor–please see page 10 for more information.
Characteristics of Response Modes
Mode 1 has very high sensitivity to carbon monoxide combined with high sensitivity to heat. This gives a high overall sensitivity to both smouldering and flaming fires.
Mode 2 is set to report the presence of carbon monoxide only.
Mode 3 has moderate sensitivity to carbon monoxide combined with low sensitivity to heat and is used for general applications.
Mode 4 has lower than normal carbon monoxide sensitivity combined with high heat sensitivity making it suitable to areas where a certain amount of carbon monoxide might be considered normal.
Mode 5 has no response at all to carbon monoxide and acts as a rate-ofrise heat detector.
Notes
1. If the Multisensor is to be used in mode 5 heat detector spacing & coverage should be applied. Observe the recommendations of BS5839: Part 1 or other applicable code.
2. The notes on carbon monoxide detectors on pages 16–17, particularly concerning application, limitations and precautions, should be read carefully.
3. In situ testing of the multisensor detector should be carried out as for CO detectors in response mode 2 and for heat detectors in response mode 5. Both CO and heat sensors must be tested in modes 1, 3 and 4.
ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ
| Detection principle: | CO: Ambient carbon monoxide level Heat: Temperature dependent resistance |
| Chamber configuration: | Horizontal optical bench housing infra-red emitter and sensor, arranged radially to detect forward scattered light |
| Supply wiring: | Two-wire supply, polarity insensitive |
| Terminal functions: | L1 & L2 supply in and out connections +R remote indicator positive connection (internal 2.2kΩ resistance to positive) –R remote indicator negative connection (internal 2.2kΩ resistance to negative) |
| Operating voltage: | 17–28V DC |
| Communication protocol: | Apollo Discovery 5–9V peak to peak |
| Quiescent current: | 400μA |
| Power-up surge current: | 1mA |
| Maximum power-up time: | 10s |
| Alarm current, LED illuminated: | 3.5mA |
| Remote output characteristics: | Connects to positive line through 4.5kΩ (5mA maximum) |
| Clean-air analogue value: | 23 +4/–0 |
| Alarm level analogue value: | 55 |
| Alarm Indicator: | 2 colourless Light Emitting Diodes (LEDs); illuminating red in alarm. Optional remote LED |
| Storage temperature: | Continuous +10 to +30°C |
| Continuous +10 to +30°C | Continuous 0°C to 50°C Transient –20° to +55°C (no condensation or icing) |
| Operating pressure: | Atmospheric pressure ±10% |
| Humidity: | Continuous 15 to 90% RH; Transient 0 to 99% RH |
| Effect of temperature on CO cell: | Less than 15% change in sensitivity over rated range |
| Effect of wind on CO cell: | None |
| Maximum CO cell life: | 7 Years (assumes regular checks are satisfactory). |
| Transport pressure: | If air freighted this detector should be carried in a pressurised hold |
| IP rating: | 44 in accordance with BSEN60529 |
| Vibration, Impact and Shock: | To EN54 |
| Approvals & Standards: | See page 29 |
| Dimensions: | 100mm diameter x 54mm height 60mm (height in base) |
| Weight: | Detector 105g Detector in base 160g |
| Materials: | Housing: White polycarbonate V–0 rated to UL94 Terminals: Nickel plated stainless steel |
