Alarm Threshold Based On The Relative Standard Deviation (Sigma Threshold) - Thermo Scientific RadEye GX Operating Instructions Manual

3.6 Alarm threshold based on the relative standard
deviation (sigma threshold)
The alarm thresholds refer to the basic display set. If the sigma
value set ranges between 2 and 9, the first alarm threshold is cal-
culated from the count rate of the background ratemeter according
to the following empirical equation:
 
1 *
As Cnt n
where As1:
Cnt:
n:
T:
Av:
Count rate Measuring
time
0...<8 cps 20 s
8...<32 cps 15s
32... 10s
<256 cps
>256 cps 5s
All count Preset time
rates constant
(1..60s)
3-18
Pi/Ff 14.09.2016

*
Cnt T Av
T
Alarm threshold 1
Count rate of the background ratemeter
sigma value set between 2 and 9
Average measuring time depending on
back ground value
Additional value (0 if linear ratemeter is enabled)
Additional
value
80
80
80
80
0
DB-074 E
ADF Linear
ratemeter
x
x
x
x
RadEye GX, GX-L
x