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KAHN INSTRUMENTS, INC.
885 Wells Road, Wethersfield, CT 06109
Tel: 860-529-8643; Fax: 860-529-1895
E-mail: [email protected]
www.kahn.com
4.4.3 Periodic ABC Operation
For process monitoring and control applications the instrument should be operated in
automatic balance mode with duration and period of the ABC cycle set by the user as
shown in section 2.7. The time settings used will depend on the application, generally the
drier and cleaner the gas the longer the ABC frequency. For most applications an ABC
frequency of 4 to 8 hours is realistic.
The ABC system will self-initiate and compensate the control electronics for build-up of
contamination on the optical surfaces. Also, it will illuminate a front panel red alarm LED
ABC STATUS when the optics loop can no longer compensate for optical contamination.
A balance cycle can be initiated at any time, regardless of when the last periodic cycle
was performed simply by pressing the front panel INITIATE button. This balance cycle
will be in addition to the periodic ABC cycles and will not reset the periodic timer.
4.4.4 On Request ABC Operation
Operation of the balance system in its On Request mode allows the user to manually
initiate a balance cycle instead of allowing the instrument to perform this task at set time
intervals. If operated in this configuration, the instrument will only perform an ABC cycle
when the user initiates the process through use of the front panel switch marked
INITIATE (see section 2.8), the Remote ABC initiate terminal on the rear panel (see
section 4.5.1) or via the RS232 interface (see section 4.5.2).
For laboratory use or calibration work it may be desirable to operate the Series 4000 in
this mode, to prevent the automatic initiation of the balance cycle causing interference
with critical measurements.
