There are many times around your home or garage when taking temperatures of an item without getting close to it or using a direct contact thermometer is necessary.
Non-Contact Infrared Thermometers try to perform this tasks. Somewhere between a thermal imager and a contact thermometer these non-contact thermometers take samples of heat signatures at a distance of one to three feet and approximate the actual heat of the object based on its signature.
The closer you are to the object the tighter the sampling area. At about one foot range you can get a 1 inch wide sample area at farther distances of 3 feet or more you get a larger sample area of three inches or more.
The accuracy of the device depends on many factors including your use in the field.
Most Infrared Thermometers can measure up to about 250°F but some can go as high as 1400°F or more.
Many of these hand-held thermometers include a laser site to place a dot in the center of the sample area. This will aid you in getting a better reading of the object you are examining.
Best Use
The first thing you have to consider is when are they best used.
Obviously you would use a meter like this when you can not get close enough to the object to measure its temperature directly.
You may want to use a non-contact thermometer when examining your car engine’s exhaust system or a coolant line or alternator you suspect may have a bad bearing.
Taking these readings must be done with caution. If you do not have a good base reading to judge against your results you may misdiagnose the problem.
Examining Electrical wiring and boxes in your home may be another use for this product along with examining your HVAC system.
One thing though when reading the temperature of forced air coming out of your ducts using a device like this may give you the temperature of the duct and not the air. For that reason a contact thermometer placed in the duct over a period of time will probably give the best reading.
Note
Diagnosing a problem is easier when the information you receive from your test equipment is both reliable and applicable.
If you take a heat measurement on a device and it is exactly correct can you use that information to diagnose the problem? Sometimes you can and sometimes you can not.
So to get the best from such a device make sure you understand not only how to operate it but how to use the information you receive to help in your diagnoses.