
C7355A ROOM IAQ MONITOR
9
31-00434—01
Fig. 14.
CORRECTION AND
CALIBRATION
Regular Correction
In order to ensure the accuracy of the measured value, the
C7355A should be corrected every year. The correction
should be carried out when a large deviation in the
measured value occurs even if it has been used for less
than one year.
This chapter describes the correction environment and
requirement needed on user's site, the correction can be
carried out by the user via RS-485.
If the following environment conditions are required for
field correction.
CORRECTION ENVIRONMENT:
Temperature: 68 °F ~ 77 °F (20 ~ 25 °C)
Humidity: 40% ~ 50% RH
The C7355A needs to be placed in the indoor natural
environment within the above temperature and
humidity range.
There should be windows and no human interference
with good air circulation.
The room area for correction should not be less than
325 ft
2
(30 m
2
).
CALIBRATION STANDARDS NEEDED FOR ON-SITE
CORRECTION.
PM2.5/PM10
PM2.5/PM10 calibration standard: TSI 8533 as a stan-
dard machine, or a new C7355A device.
After the new C7355A and the old C7355A that needs
to be corrected are powered on continuously and
synchronously for more than 10 minutes, record the
PM2.5 value for 30 minutes, and synchronous aver-
age value over 30 minutes can be applied for correc-
tion.
Temperature and humidity
Temperature and humidity calibration standard:
commercial or industrial temperature and humidity
calibration standard.
After the temperature and humidity calibration stan-
dard and C7355A that needs to be corrected are
powered on continuously and synchronously for
more than 60 minutes, start to record the value of
temperature and humidity for 10 minutes, use the
synchronous average value within 10 minutes over
correction.
CO
2
CO
2
calibration standard: e.g. CO
2
transmitter. Outdoor
CO
2
reference value is about 380 ppm-420 ppm.
After the CO
2
calibration standard and C7355A that
needs to be corrected are powered on continuously
and synchronously for more than 48 hours, the CO
2
value shall be continuously recorded for 30 minutes,
use the synchronous average value over 30 minutes
for correction.
TVOC
TVOC calibration standard: Because each TVOC uses
different sensors and sensitive substances, it is rec-
ommended to use the new C7355A machine as the
TVOC calibration standard.
After the TVOC and C7355A that needs to be corrected
are powered on continuously and synchronously for
more than 48 hours, record the TVOC value continu-
ously for 30 minutes and use the synchronous aver-
age value over 30 minutes for correction TVOC value
will be stable only after correction and at least 24
hours power-on.
Table 3. DIP Switch Settings
Indicator
Lights
DIP4 DIP3 DIP2 DIP1
Indicator
Lights
OFF OFF OFF OFF OFF
Three-color Indicator
Lights
OFF ON ON ON Default
Green Indicator Lights
Normally ON
ON OFF OFF OFF