Concepteur de solutions ATEX et industrielles
Contact : +33 (0) 4 88 78 21 81

Orbis I.S. Heat Detector


Orbis I.S.

Intrinsically Safe Heat Detector

  • TimeSaver® Base
  • Patented FasTest® enabling functional testing in four seconds
  • DirtAlert® indicates limit of drift compensation
  • Tolerates extreme operating conditions: -40°C to +70 °C
  • False alarm reduction Flashing LED option
  • Warranty 10 years
Datasheet : Orbis I.S. Heat Detector (EN)

The Orbis IS Heat Detector monitors temperature by using a single thermistor network which provides a voltage output proportional to the external air temperature. The Orbis IS range incorporates seven heat detector classes to suit a wide range of operating conditions.

Key Features :

  • Can be used for applications where smoke detectors are unsuitable
  • Ideal for environments that are dirty or smoky under normal conditions
  • Reduced incidences of false alarms
  • Increased reliability of detection

Operation :

Orbis I.S. heat detectors have an open-web casing which allows air to flow freely across a thermistor which measures the air temperature every 2 seconds. A microprocessor stores the temperature and compares them with per-set values to determine whether a fixed upper limit – the alarm limit – has been reached.

In the case of rate-of-rise detectors the microprocessor uses algorithms to determine how fast the temperature is increasing.

Static heat detectors respond only when a fixed temperature has been reached. Rate-of-rise detectors have a fixed upper limit but they also measure the rate of increase in temperature. A fire might thus be detected at an earlier stage then with a static detector so that a rate-of-rise detector is to be preferred to a static heat detector unless sharp increases of heat are part of the normal environment in the area protected by the heat detector.


The Orbis I.S. range incorporates seven heat detector classes to suit a wide variety of operating conditions in which smoke detectors are unsuitable.

The European standard EN54-5:2000 classifies heat detectors according to the highest ambient temperature in which they can safely be used without risk of false alarm. The classes are identified by the letters A to G. (Class A is subdivided into A1 and A2.) In addition to the basic classification, detectors may be identified by suffix to show that they are rate-of-rise (suffix R) or fixed temperature (suffix S) type.

All heat detectors in the Orbis I.S. range are tested as static or Rate-of-rise detectors and are classified as A1R, A1S, A2S, BR, BS, CR and CS.

Environmental Characteristics

The environmental performance is similar to that of the Orbis I.S. optical smoke detector but it should be noted that heat detectors are designed to work at particular ambient temperatures. Also classification and BASEEFA certificate number are the same as for the optical smoke detector.

Operating and storage temperature: –40°C to +70°C

Operating temperature is restricted by the intrinsic safety gas classification.
Class T5: –40°C to +45°C
Class T4: –40°C to +60°C

The detector must be protected from conditions of condensation or icing.


General applications

  • Dusty environments
  • Dangerous areas
  • Offshore platforms
  • Refineries
  • Small and medium buildings


Maximum power-on time <20 seconds
Quiescent current: 80μA
Quiescent current tested at: 24 V DC
Sampling frequency: once every 2 seconds
Polarity L1 and L2 is sensitive to polarity
Minimum voltage of the “active detector”: 12 V
Holding voltage (min.): 5 V
Minimum voltage to light the alarm LED: 6V
Alarm reset voltage: <1 V
Alarm reset time: 1s
Alarm load: 325 Ω in series with a drop of 1.0 V


Humidity: 0% to 98% (no condensation or icing)
Nominal value: IP IP23D
Storage temperature: -40 ° C to + 70 ° C




Weight: 70g
Colour: White
Materials: Polycarbonate housing
Product length: 42 mm
Product diameter: 100 mm
Detection principle: Temperature sensitive resistance.



A2S (Advanced Safety Solutions) 350 Avenue JRGG de la Lauzière 31 Parc du Golf - CS 90519 13593 Aix en Provence Cedex 3


Tél: +33 (0)4 88 78 21 81 Fax: +33 (0)4 42 16 35 09 E-mail :
Contact par email
Formulaire de contact
Contact par téléphone