RKI Instruments Beacon 410 - Manual (Page 50)

46 • Detector Head Types Beacon 410 Gas Monitor Operator’s Manual
detection using catalytic combustion type detectors, if potential catalyst poisons are
known or likely to be present, more frequent calibration than every 3 months will be
necessary.
Detector Head Types
The Beacon 410 can support both direct connect (internal amp) and 4-20 mA transmitter
(remote amp) detector heads. Since the Beacon 410 can support both types of detector
heads, there are three possible detector head combinations when calibrating the active
channels:
• Direct connect detector heads only.
If all the active channels are direct connect detector heads, then all calibration
adjustments are made at the Beacon 410 after calibration gas is applied to the
detectors.
• 4-20 mA transmitter detector heads only.
If all the active channels are 4 - 20 mA transmitter detector heads, then all calibration
adjustments are made at the detector head when calibration gas is applied to the
detectors.
• Direct connect and 4-20 mA transmitter detector heads.
If both direct connect and 4-20 mA transmitter detector heads are installed, then
calibration adjustments must be made at the Beacon 410 for the direct connect
detector heads after applying gas to the detectors, and at the detector heads when
gas is applied for the 4-20 mA transmitter detector heads.
Calibration Gas Response Memory
Feature
When a direct connect detector head is installed, the Beacon 410 has the capability to
“remember” the detector’s response to the calibration gas after the gas is removed from
the detector during the fresh air or span (zero for an oxygen detector) adjustment
procedure. This feature enables one person to perform calibration if the detector heads
are mounted remotely from the Beacon 410. When zero air is applied to a detector head
during a fresh air adjustment in Calibration Mode, the Beacon 410 will freeze the display
reading at the lowest (highest for an oxygen detector head) response and the Beacon 410
will continue to display this reading and retain it in its memory until the fresh air adjustment
procedure is completed. When calibration gas is applied to a detector head during a span
(zero for an oxygen detector) adjustment in Calibration Mode, the Beacon 410 will freeze
the display reading at the highest (lowest for an oxygen detector) response to the
calibration gas. The calibration gas can then be removed and the Beacon 410 will
continue to display this reading and retain it in its memory until the span (zero for an
oxygen detector) adjustment procedure is completed.