COSA Xentaur COSA 9610 - Manual (Page 10)

INSTALLATION, OPERATION AND MAINTENANCE MANUAL – COSA 9610™
Page 10 of 44
1.4. E
XTENDED
(D
UAL
) R
ANGE
O
PTION
1.4.1. Operation
When the measuring range of the analyzer is larger than 1150BTU/SCF, an extended range
option is available which covers a Wobbe index of 3000.BTU/SCF. This is accomplished by
adding a second gas-mixing orifice and selection valves to make changeover possible.
The dilution ratios of each mixing orifice are chosen such that the measuring ranges overlap.
Via the software it is possible to create a 4/20mA current loop signal that covers the whole range.
It is necessary to establish a switch over point that must be calibrated.
For this reason the calibration system is expanded with an extra solenoid valve.