Welch Allyn LC101 CO2 Module - User Manual - Manual (Page 21)

LC101 CO
2
Module OEM Implementation Manual Section 3 - LC101 Calibration
Welch Allyn OEM Technologies Confidential Page 21
Two-Point User Calibration
NOTE Before performing a Two-Point User Calibration, a separate Zero Calibration must be
performed first. It is also recommended that both calibrations be performed at 75ºF in
order to maintain accuracy over the Module’s operating temperature range.
The Two-Point User Calibration, or User Calibration, updates two of the gas calculation constants
used to generate the CO
2
values. The required frequency of User Calibration depends on the
amount and type of usage. Typically it may be required every six months. The LC101 does not
monitor time between calibrations, nor does it alert the host when calibration is needed. It is up
to the host system and the end-user to determine when calibration is required.
To get an accurate User Calibration, the LC101 needs to be operating for at least 5 minutes in
measurement or autorun mode. The LC101 internally monitors the run time and will not allow a
User Calibration if the run time requirement has not been met.
To perform the User Calibration, the host is required to supply a calibration date, a span gas
concentration, and indicate the gas concentration being applied to the LC101 Module (0% or the
span gas).
The OEM typically provides a User Calibration Kit to the end user containing a CO
2
reference
gas with regulator, scrubber, directions for use, adapter, and tubing.
The LC101 monitors the User Calibration progress and provides a “Calibration OK” (or “not OK”)
message to the host system after successful calibration when polled for status. See the LC101
Software Protocol and the User Calibration Commands and Responses for more detail. After a
successful User Calibration, the LC101 updates the User Calibration History Queues located in
the LC101 C-Cap EEPROM Memory.
Zero and User Calibration dates should be user accessible via a host service screen or other
means.