8.4
Working with alarms
You can choose between the following alarm outputs:
■
a silent alarm, which, will make the background of the corresponding measurement
function turn red when an alarm is triggered
■
an audible alarm, which, compared to the silent alarm, also triggers a ’beep’
A settings can also be made in the camera so that an alarm output takes into account
the reference temperature. A typical application when you would want to use an alarm
that takes into account the reference temperature is screening of people for face
temperature detection.
Firstly, the reference temperature is set by screening 10 persons with normal face
temperature. The camera puts each of these 10 results in an internal camera buffer
and calculates the average temperature value after having discarded the two highest
and two lowest values in the event of erroneous samples. Every time a new sample
is saved to the internal buffer, the oldest sample will be discarded and a new reference
temperature will be calculated ’on the fly’.
Using an alarm that takes into account the reference temperature means that an alarm
output will only be triggered if the temperature value exceeds the sum of the average
temperature value in the the user-defined delta alarm offset value.
8.4.1
Setting the reference temperature
Action
Step
Press the joystick to display the menu bar.
1
Point to
Buttons
on the
Setup
menu and press the joystick.
2
In the
Buttons setup
dialog box, press the joystick up/down to go to
F1
or
F2
.
3
Press the joystick left/right to select
Update ref temp
.
4
Press the joystick to confirm the choice and leave the dialog box.
5
Now point to
Image
on the
Setup
menu and press the joystick.
6
Press the joystick up/down to go to
Shutter period
.
Although the shutter period works independently of other functions described in
this document, FLIR Systems recommends that
Short
is selected when using the
camera for detection of face temperature.
➲
Selecting
Normal
will calibrate the camera at least every 15th minute, while se-
lecting
Short
will calibrate the camera at least every 3rd minute.
7
Pointing the camera to the first person with a normal face temperature and pressing
the
F1
or
F2
button will display the message
Sampled nn.n °C
.
8
8
52
Publ. No. 1558240 Rev. a156 – ENGLISH (EN) – March 1, 2006
8 – Tutorials
