Endress+Hauser gammapilot FTG 671, Руководство по эксплуатации

Страница: 17 / 64

Detector DG 57 The use of a rod scintillator for detection of the gamma rays allows the lowest source
strengths to be used for limit switching. The heart of the DG 57 is a cylindrical rod 48 mm
in diameter made of transparent synthetic scintillation material. For limit detection a length
of 100 mm or 400 m is used. For hot environments (> 40°C) it is recommended that the
version with a water-jacket is used (flowrate 40-200 l/h; max. water temperature 40 °C;
water pressure 4-6 bar).
The detector generates a pulse code modulation signal which is sampled by the FTG
transmitter at intervals of 500ms. Prior to each sampling cycle a light pulse generated
by a LED is sent through the scintillator to generate a reference value. The reference
value, temperature and pulse rate are transmitted digitally via a two-wire connection to
the transmitter FTG 671.
BA082D08
Scintillation rod produces flashes
when gamma radiation impinges
on it
Connection to FTG 671 Outer stainless steel encapsulation
Photomultiplier
Detector head
varies according to
version
Temperature
sensor
Reference diode
Fig. 2.3:
Function of the DG 57 rod
scintillation counter
Overall lenght B = A + 673
±
5
Measuring lenght A
Ø
110
Ø 8
0
approx 500
100
144
1
12
A = /100 /400
BA082E55
110
Fig. 2.4:
Dimensions in mm
Detector DG 57
Ø
108
20
120
approx 500
177
125
12
Overall lenght B = A + 682
±
3
Measuring lenght A
A = /100 /400
BA082E44
Fig. 2.5:
Dimensions in mm
Detector DG 57 with
water jacket
Gammapilot FTG 671 Chapter 2: Installation
15