Search results
Results from the WOW.Com Content Network
A residential heat detector. A heat detector is a fire alarm device designed to respond when the convected thermal energy of a fire increases the temperature of a heat sensitive element. The thermal mass and conductivity of the element regulate the rate flow of heat into the element. All heat detectors have this thermal lag. Heat detectors have ...
Inset shows false color infrared thermograph of a roof on a sunny day; the white surfaces (colored blue in the thermograph) have been coated with an elastomer to reduce solar loading and have a surface temperature of approximately 60 °F (16 °C); the gray surfaces (colored red/white in the thermogram) are a standard asphalt (bitumen) coating and have a surface temperature of approximately 160 ...
Fire alarm systems are required in most commercial buildings. They may include smoke detectors, heat detectors, and manual fire alarm activation devices (pull stations). All components of a fire alarm system are connected to a fire alarm control panel. Fire alarm control panels are usually found in an electrical or panel room.
Active thermography is an advanced nondestructive testing procedure, which uses a thermographic measurement of a tested material thermal response after its external excitation. This principle can be used also for non-contact [1] infrared non-destructive testing (IRNDT) of materials. [2]
The heat generated dissipates into the sample on both sides of the sensor, at a rate depending on the thermal transport properties of the material. By recording temperature vs. time response in the sensor, the thermal conductivity, thermal diffusivity and specific heat capacity of the material can be calculated.
For smoke detectors according to EN 54-7 and fire detectors with smoke sensor (parts 12, 20 and 30 of EN 54) the test fires TF2, TF3, TF4 and TF5 are used. The EN 54-20 defines the following test fires with reduced fuel quantity for aspirating smoke detectors with enhanced or very high sensitivity (class A or B):
IEC 60068 is an international standard for the environmental testing of electrotechnical products that is published by the International Electrotechnical Commission (IEC).. IEC 60068 is a collection of methods [1] for environmental testing of electronic equipment and products to assess their ability to perform under environmental conditions including extreme cold and dry heat.
In a vertical setup, a light source (e.g. laser, flashlamp) heats the sample from the bottom side and a detector on top detects the time-dependent temperature rise. For measuring the thermal diffusivity, which is strongly temperature-dependent, at different temperatures the sample can be placed in a furnace at constant temperature.