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© 2022 All rights reserved. Data subject to change without notice.
LPT-M - Operation Manual
Rev. B | 2022.03
directing span gas into the sensor may result in slightly higher readings. It is
important to note that the type of gas mixture, how old the gas is and what
temperature it has been stored at will also affect repeatability during field
calibration.
NOTE:
Oxygen sensors require 99.9% N
2
for a true zero and span is done first,
followed by zero.
NOTE:
Catalytic sensors require oxygen to work and thus the user MUST flow
clean air or oxygen to obtain a true zero and the span gas must have “air”
balance, not N
2
balance.
7.1.2 Regulators & Flow
Calibration gases that are lighter than or the same weight as air (CO, O
2
, etc.)
should be flowed at 0.5 LPM. Gases heavier than air (NO
2
, etc.) should be
flowed between 0.5 and 1.0 LPM. Fixed flow regulators provide more accuracy.
7.1.3 Adapters
The proper calibration adapter should be utilized to allow the gas to properly
diffuse around the sensor. The calibration adapter plug for an LPT-M with an
internal sensor without a splash guard is part number
CET-7000-CAP
. For an
LPT-M with a splash guard, use part number
CET-4700-SCC
or use the Cal Clip
hands free adapter, part number
CET-SGC
.
7.1.4 Calibration Frequency
• Parking garage detectors: Once every 12 months
• OHS applications: Once every 6 months (OHS: Occupational
Health & Safety)
•
For best performance and to meet published specifications:
once every six months
NOTE:
A calibration label should be applied after every calibration to confirm
work performed and the date it was confirmed. If a controller is involved,
