EXTECH
INSTRUMENTS
EX850-en-GB_v2.4 7/16
8
Non
‐
Contact
InfraRed
Temperature
Measurements
1.
Set
the
function
switch
to
the
IR
Temp
position.
2.
Aim
the
infrared
sensor
(rear
of
the
meter)
at
the
surface
to
be
measured.
3.
Press
the
button
in
the
center
of
the
rotary
function
switch
to
turn
on
the
laser
pointer
and
identify
the
surface
spot
to
be
measured.
4.
The
area
of
the
surface
to
be
measured
must
be
larger
than
the
spot
size
as
determined
by
the
distance
to
spot
size
specification.
5.
Read
the
temperature
in
the
display.
Note:
See
the
“Temperature
Units”
paragraph
to
select
o
F
or
o
C
WARNING:
Do
not
directly
view
or
direct
the
laser
pointer
at
an
eye.
Low
power
visible
lasers
do
not
normally
present
a
hazard,
but
may
present
some
potential
for
hazard
if
viewed
directly
for
extended
periods
of
time.
IR
Spot
to
Distance
Diagram
The
8:1
spot
to
distance
ratio
determines
the
size
of
the
measured
surface
area
with
respect
to
the
distance
the
meter
is
held
away
from
the
surface.
IR
Measurement
Notes
1.
The
object
under
test
should
be
larger
than
the
spot
(target)
size
calculated
by
the
field
of
view
diagram.
2.
If
the
surface
of
the
object
under
test
is
covered
with
frost,
oil,
grime,
etc.,
clean
before
taking
measurements.
3.
If
an
object's
surface
is
highly
reflective,
apply
masking
tape
or
flat
black
paint
to
the
surface
before
measuring.
4.
The
meter
may
not
make
accurate
measurements
through
transparent
surfaces
such
as
glass.
5.
Steam,
dust,
smoke,
etc.
can
obscure
measurements.
6.
To
find
a
hot
spot,
aim
the
meter
outside
the
area
of
interest
then
scan
across
(in
an
up
and
down
motion)
until
the
hot
spot
is
located.
10cm
1.25cm
20cm
2.5cm
60cm
7.5cm
Distance to object
Diameter of spot
