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The Calibration Menu
1. Sensor Zero
Select this option to Zero a particular sensor.
The expected sequence will be:
Select ZERO SENSOR function
Select the channel to ZERO
Flow zero gas at the sensor and allow to stabilise
Select to ZERO
Observe the result
See enclosed Zero-Cal Data
2. Zero All
Selecting this function will automatically perform a zero on all connected detectors. Typically this is
only used during commissioning when it is known that there is no target gas present. This function
should NOT be used in general calibration as there is the danger when an installation is up and
running that you could be zeroing off a valid gas reading.
3. Calibrate Sensor
Select this option to Calibrate a particular sensor.
The expected sequence will be:
Select CALIBRATE SENSOR function
Select the channel to CALIBRATE
Flow calibration gas at the sensor and allow to stabilise
Select to CALIBRATE
Observe the result
See enclosed Zero-Cal Data
4. One Man Calibration
This function allows one person to calibrate a sequence of detectors by selecting the function then
applying gas to each detector in turn for 3 minutes. The Tocsin 920 monitors the signal from the
detectors and performs the calibration automatically once it sees a valid steady reading. This is
similar in operation to the walk test function on a smoke detection panel.
For full details see later section.
It is recommended that after installation the system is commissioned by an IGD qualified service
engineer. The service interval is 6 months including calibration of all connected gas sensors by a
suitably qualified service engineer.
