Endress+Hauser gammapilot FTG 671, Руководство по эксплуатации

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Limit switch/
Acknowledgement mode The choice between standard or acknowledged operation, see Section 5.2, is made at
field V1H2 for relay 1 and V1H7 for relay 2:
•
0 = standard operation (default)
•
1 = acknowledgement mode
Step Matrix Entry Significance
1 V1H2 e.g. 0 Selects standard mode (limit swich) for relay 1
2 - »E« Registers entry
Relay at fault When the self-monitoring circuit triggers on a fault, the relay adopts the behaviour set at
V1H3 for relay 1 and V1H8 for relay 2:
•
Setting 0 = de-energised
•
Setting 1 = remains in the status found when the alarm relay de-energised
Step Matrix Entry Significance
1 V1H3 e.g. 0 The relay de-energises on alarm
2 - »E« Register entry
Integration time The integration time is entered at V0H4 as follows:
Step Matrix Entry Significance
1 V0H4 10 Integration time set to 10 seconds
2 - »E« Register entry
The determination of the integration time depends upon the detector connected:
•
For the DG 57 detector, determine the maximum relay response time
(0
…
300s) your process will tolerate. Enter this plus 2 s as the integration time.
- Figs 5.3
…
5.6 can be used to check at which local dose rate the warning
E635 (integration time too short) appears.
•
For the DG 17/27 detector, the local dose rate determines the minimum re-
sponse time of the relay, see Fig. 5.7
…
5.10. The integration time acts as a pro-
longation factor, which increases the response time 1
…
6 fold.
Read the minimum response time
τ
from Fig. 5.7
…
5.10, then determine the
maximum relay response time your process will tolerate
τ
max
.
Prolongation factor =
τ
max
/
τ
Enter this factor rounded to next integer value in V0H4.
Half value layer
(Figs 5.3
…
5.10)
Figs. 5.3
…
5.10 show the required local doserate at the detector as a function of relay
response time, source type and detector type.
•
The faster the response time, the higher the required local doserate
•
If the HVLvalue is less than 4, the local doserate at the detector increases,
see Fig. 5.11.
For the Cs 137 source, 4 HVL = d
i
x
ρ
medium
≥
450, for Co 60, 4 HVL = d
i
x
ρ
medium
≥
620, whereby d
i
= path length through medium (mm) and
ρ
= density of medium
(g/cm
3
)
Gammapilot FTG 671 Chapter 5: Limit Switches - Relays
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