Hardware Reference
In-Depth Information
issues are causing problems. The simplest and best tool I've found for the job is the digital
thermometers sold at most auto parts stores for automobile use. They are designed to read the
temperature inside and outside the car and normally come with an internal sensor, as well as one at
the end of a length of wire.
Normally, the maximum limit for internal air temperature should be 110°F (43°C) or less. If your
system is running near or above that temperature, problems can be expected.
Infrared Thermometer
Another useful temperature tool is a noncontact infrared (IR) thermometer, which is a special type of
sensor that can measure the temperature of an object without physically touching it (see
Figure 20.9
)
.
You can take the temperature reading of an object in seconds by merely pointing the handheld device
at the object you want to measure and pulling a trigger.
Figure 20.9. A noncontact infrared thermometer.
An IR thermometer works by capturing the infrared energy naturally emitted from all objects warmer
than absolute zero (0° Kelvin). Infrared energy is a part of the electromagnetic spectrum with a
frequency below that of visible light, which means it is invisible to the human eye. Infrared
wavelengths are between 0.7 microns and 1,000 microns (millionths of a meter), although infrared
thermometers typically measure radiation in the range 0.7-14 microns.
Because IR thermometers can measure the temperature of objects without touching them, they are
ideal for measuring chip temperatures in a running system—especially the temperature of the CPU
heatsink. By merely pointing the device at the top of the CPU and pulling the trigger, you can get a
very accurate measurement in about 1 second. To enable more accuracy in positioning, many IR
thermometers incorporate a laser pointer, which is used to aim the device. IR thermometers like the
