Critical Environment Technologies LPT-M, Руководство по эксплуатации

Страница: 54 / 72

54 © 2020 All rights reserved. Data subject to change without notice.
LPT-M - Operation Manual Rev. B | 2020.11
using gas cylinder, regulator and hose 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 aff ect repeatability during fi eld calibration.
NOTE:
• Oxygen sensors require 99.9% N
2
for a true zero and span is done fi rst, followed by zero.
• Catalytic sensors require oxygen to work and thus the user MUST fl ow 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 fl owed at
0.5 LPM. Gases heavier than air (NO
2
, etc.) should be fl owed between 0.5 and 1.0 LPM. Fixed fl ow
regulators provide more accuracy.
7.1.3 Adapters
The proper calibration adapter should be utilized to allow the gas to properly diff use 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 specifi cations: once every six months
NOTE: A calibration label should be applied after every calibration to confi rm work performed and
the date it was confi rmed. If a controller is involved, the alarm set points should be indicated on a
label on the front door of the enclosure so anyone working in the environment can be aware.