Jenoptik VARIOSCAN high resolution Series, Manual

Page: 52 / 57

Temperature measurement
52
By varying the offset value, the user can adjust the temperature display
of the camera to the actual temperature value. As this offset acts on the
radiant power on which temperature calculation is based, unknown
fractions of extraneous radiation are easily compensated.
object camera
1
2
3
environment
air path
(1) Direct radiation of measured object:
( )
λ ∗ τ ∗ ε
, T P
o P o
with
1000
ce tan dis ap
p
e
∗ −
= τ
(2) Ambient radiation reflected by measured object:
( ) ( )
λ ∗ τ ∗ ε −
, T P 1
A p o
(3) Characteristic radiation of air path:
( ) ( )
λ ∗ τ −
, T P 1
p p
Total radiation:
( ) ( ) ( )
( ) ( )
u p p A p o o p o 1
O , T P 1 , T P 1 , T P P
+ λ ∗ τ − + λ ∗ τ ∗ ε − + λ ∗ τ ∗ ε =
When you switch-on the VARIOSCAN high resolution , a calibration file
is loaded containing the temperature-relevant parameters of the current
camera configuration. This file also contains the thermal characteristic
of the camera set up of 20 calibration points distributed over the entire
temperature measuring range and the corresponding conditions of
calibration. Subsequently, all other temperatures are derived by
InfraTec