3 Description
B4
1001305a
B4 Density
monitor
W2 Test
connection
Fig. 21
Test connection W2 (view with cover of the contact
position indicator removed)
3.8.2.1 Function of the Density Monitor
The density monitor compares the density of the SF
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gas in the compartment to be monitored with the density of
reference gas enclosed inside the monitor. Both gases are exposed to the same ambient temperature. The
density comparison is replaced by a pressure comparison in both systems (gas compartment - reference
compartment).
The density monitor responds to a change in pressure as a result of a leak between circuit-breaker gas
compartment and atmosphere. Pressure changes as a result of temperature changes are not taken into account.
The density monitor is set at the works to the limit density required. Resetting is neither necessary nor possible.
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