Sentry ST-677, Instruction Manual

Page: 14 / 18

5.2 Emissivity
10
6. Maintenance
Cleaning the lens: Blow off loose particles using clean
compressed air. Gently brush remaining debris away
with a camel's hair brush. Carefully wipe the surface
with a moist cotton swab. The swab may be moistened
with water.
NOTE:
DO NOT use solvents to clean the lens.
Cleaning the housing:
Use soap and water on a damp sponge or soft cloth.
Non-contact temperature sensors measure IR energy emitted
by the target, have fast response, and are commonly use to
measure moving and intermittent targets, targets in a vacuum,
and targets that inaccessible due to hostile environments,
geometry limitations, or safety hazard. The cost is relatively
high, although in some cases is comparable to contact devices.
Emissivity is the ability of an object to emit or absorb
energy. Perfect emitters have an emi ssivi ty of 1 ,
emitting 100% of incident energy. An object with an
emissivity of 0.8 will absorb 80% and reflect 20% of
ra the incident energy. Emissivi y is def ined as t he tio t
of the energy radiated by an object at given
temperature to the energy emitted by a perfect
radiator at the same temperature. All values of
emissivity fall between 0.0 and 1.0.