COSA Xentaur COSA 9610 - Manual (Page 20)

INSTALLATION, OPERATION AND MAINTENANCE MANUAL – COSA 9610™
Page 20 of 44
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Caution
The adjusting screw is located in the gas compartment of the relay. When the insert is
released, gas will escape. Be prepared before the relay is going to be adjusted, e.g. have
the right equipment readily available, so the gas compartment has to be open for only a
minimum of time.
After this adjustment the insert must be fitted again and the offset can be checked. The
offset adjustment can be checked by reading the air and gas pressure indicators. This
operation must be repeated until the desired residual oxygen concentration is reached.
After this the insert is fitted with sealing tape, assembled and then checked for leakage by
means of either a gas leak detector or soap.
It is advisable; to carry out a check on the booster relay adjustment with high Wobbe-
Index calibration gas, directly after setting up the booster set point. Using the on-screen
menu, select 2 Points manual (Dual Range manual for dual range analyzer) validation.
Proceed to the “Wait for cal gas 2 to stable” step (“Wait for cal gas 3 to stable” for dual
range analyzer). When the signals become stable, the display will show the Residual O2
mV-value suitable to this calibration gas. The setting of the booster relay is right when the
mV-value stays below 67 mV. If not, a positive offset should be set with help of the
booster relay, so that relative more air will be added and the mV value will fall.
The required Residual O2 mV-signal should be around 65mV for the highest expected
Wobbe value.