Center Model 358 Infra-red Thermometer POCKET VERSION

Inexpensive excellent quality infra-red pocket hand gun Rough laser Targeting for precise measurement Target Distance to spot ratio is 5:1 LCD display Responce time 500mS ºC or ºF Selectable Automatic Power off Display Hold Function Range -18~315 ºC Accuracy ± 2.5 ºC Resolution 0.5 ºC Emissivity ....Preset at 0.98

What is Emissivity?

Emissivity of a material is a measure of the ability of the material to emit infra red rays. It turns out that a matt black body is the best reflector of the rays with varying other surfaces having different abilities. The bottom line is that different surfaces have different emissivity ratios. As a result when using infra red thermometers the emissivity setting can affect the accuracy of measurement. There are therefore two types of infra red thermometers, those with fixed emissivity settings like ours and then a more expensive range where you can match the thermometers emissivity setting to suit the surface you will be measuring. There are tables online that give the emissivity values of most common surfaces.
Experience has shown that a good average emissivity setting is 0.98 that will suit most general applications for general use. Our two models have this setting. If the purpose of your task is to get a reasonably accurate measurement then this is fine. If however you are after the most accurate measurement to the last degree then look for thermometers with adjustable emissivity settings.
Our infra red thermometers are suited to rough and ready measurement intended to give a good idea of temperature but not laboratory type measurements. If for example you want to measure the temperature of a silver shaft a way around this problem is to simply paint a section black. Problem solved. Hope this helped.

A link to a table that gives some common values