How does pyrometer works?

Question Posted / jerry

1 Answers
7587 Views
I also Faced
E-Mail Answers

How does pyrometer works?..

Answer / malikji

Pyrometer, an instrument for measuring temperature. Although
the term pyrometer is generally considered to apply to
instruments that measure high temperatures only, some
pyrometers are designed to measure low temperatures. Two
common types of pyrometers are the optical pyrometer and the
radiation pyrometer.

A heated object gives off electromagnetic radiation. If the
object is sufficiently hot, it will give off visible light,
ranging from dull red to blue-white. Even if the object is
not hot enough to glow, however, it gives off infrared
radiation.

An optical pyrometer determines the temperature of a very
hot object by the color of the visible light it gives off.
The color of the light can be determined by comparing it
with the color of an electrically heated metal wire. In one
type of pyrometer, the temperature of the wire is varied by
varying the strength of the current until the operator of
the instrument determines that the color of the wire matches
the color of the object. A dial, operated by the current
that heats the wire, indicates the temperature.

A radiation pyrometer determines the temperature of an
object from the radiation (infrared and, if present, visible
light) given off by the object. The radiation is directed at
a heat-sensitive element such as a thermocouple, a device
that produces an electric current when part of it is heated.
The hotter the object, the more current is generated by the
thermocouple. The current operates a dial that indicates
temperature