Duomo Vent Check Plus User manual

Keypad (Fig. 1)
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5 6
4
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A
B C
C
B
A
CB
A
A
B C
C
B
A
CB
A
Vent Check Plus
Operation
Display
Press button 1 to turn the meter
on and off.
After a 30 second warm-up the
meter is ready to use and will
display the normal operating
screen (Fig. 2).
Pressing button 4 will cycle through current air
temperature, dew point and wet bulb temperature.
Pressing button 6 will cycle through minimum CO2,
maximum CO2, Time Weighted Average (TWA -
weighted average of CO2in the past 8 hours) and Short
Time Exposure Limit (STEL - weighted average of CO2in
the past 15 minutes) readings since power on.
Pressing button 5 will hold all current readings except
TWA and STEL.
Pressing and holding button 2 for more than a second
will turn the backlight on and off.
The unit will turn off automatically after 20 minutes of
inactivity.To override this function, turn the unit off then
restart it by holding buttons 1 and 5 together.
The meter will take a new reading every second. When
the operating conditions change, the unit will respond
in 30 seconds for CO2and 30 minutes for humidity.
When battery supply is low, 'Lob' will be displayed.
Change the batteries or connect the DC adaptor.
NOTE: Do not hold the meter close to the face as
exhalation can affect CO2readings.
Normal Operation (Fig. 2)
Menu Mode - Top Level (Fig. 3)
Menu Mode - Lower Level (Fig. 4)
A= CO2reading in ppm
B= Temperature, Dew
Point & Wet Bulb
Temperature
C= Relative Humidity
A= Menu name
B= N/A
C= Menu level (e.g. P 1.0)
A= Current value
B= Current menu name
C= Menu level (e.g. P 1.1)
Triple displays of CO2, temperature and
relative humidity
Stable NDIR sensor for CO2detection
Statistics of weighted averages
BS8494 compliant (from 10 - 60 ºC)
Backlight for working in dark areas
Audible CO2warning alarm
Easy manual fresh air correction on CO2
and humidity
PC connection via USB interface
With hard case and power adaptor
w: www.duomo.co.uk - e: [e-mail] - t: 01905 797989 - f: 01905 774296 | ©Duomo (UK) Ltd. 2007

Troubleshooting
Specification
Can't power on
Press button 1 for more than 0.3 seconds and try
again. Check whether batteries are in good contact
and correct polarity is observed.
Fixed readings
Check whether data hold function was activated.
Slow response
Check whether the air flow channels on the rear are
blocked.
Error messages
E01: CO2sensor damaged
E02:The value is under range
E03:The value is over range
E04:The original data error results in this error
E07: Voltage to measure CO2. Replace batteries or
use an adaptor
E11: Retry humidity calibration
E17: Retry CO2calibration
E31:Temperature sensor damaged
E34: Humidity sensor damaged
CO2
Range of 0 - 9999ppm
(maximum alarm threshold 9900ppm)
Resolution of 2ppm
Accuracy ± 30ppm Vent Check Plus ±5%
Temperature
Range of -10 - 60 ºC (14 - 140 ºF)
Resolution of 0.1 ºC (0.1 ºF)
Accuracy ± 0.1 ºC
Humidity
Range of 0.0 ~ 99.9%
Resolution of 0.1%
Accuracy ± 3% (10~90%), ± 5% (others)
Warm Up
30 seconds
Operating Ranges
From 0 ~ 50 ºC , 0 ~ 95% RH (avoid condensation)
Storage
From -20 ~ 60 ºC , 0 ~ 99% RH (avoid condensation)
Power
4 pcs AA batteries,DC Adaptor
Battery Life
> 10 hours (Alkaline)
Fresh Air Correction & Calibration
CO2Fresh Air Correction
It is strongly suggested that the unit be corrected in a
sunny, outdoor environment that is well ventilated. Do
not correct the unit in places crowded with people or
close to areas with high CO2concentration such as
ventilating outlets or fireplaces.
To correct the unit for CO2, place the meter in the
calibration site and press and hold buttons 2 and 3
simultaneously. The unit will flash continually for about
5 minutes,then return to normal operation.
To abort correction at any time, simply turn the meter
off.
CAUTION: The meter is corrected at ambient air of
around 400ppm. Do not correct the meter in an
environment with an unknown CO2concentration.
Doing this could lead to inaccurate measurements.
Relative Humidity Correction
The unit is calibrated with 33% and and 75% salt
solution. It is recommended that the unit is calibrated
at 25 ºC and at a stable humidity.
To calibrate the unit, plug it into a 33% salt bottle then
press and hold buttons 3 and 4 simultaneously.The unit
will blink continuously for about 60 minutes.
Once this has completed, plug the bottle into a 75%
salt bottle and press button 6 to begin the next
calibration stage.
It is possible to perform only one calibration test at a
time. To calibrate just 33% salt solution, press button 3
after it has finished the first stage. To calibrate just 75%
salt solution, press button 2 or 4 within 5 minutes of
33% calibration having begun.
To abort calibration at any time, simply turn the meter
off.
CAUTION: Do not calibrate the unit without the default
calibration salt. Doing so can cause permanent
damage. Contact the dealer for calibration salt.
Setup
To enter the setup mode (Fig. 3) press and hold button 1
for more than a second.
From here use buttons 2 (UP) and 4 (DOWN) to cycle
through the menu screens and button 6 to accesss the
selected menu screen (Fig.4).
Buttons 2 and 4 can then be used to alter the alarm
threshold on menu P 1.1 and the temperature scale on
menu P 3.1 (Fig.4).
Use button 6 to save the current setting and return to
the main menu screen (Fig. 3).
Press button 3 at any time to exit the setup menu.
w: www.duomo.co.uk - e: [e-mail] - t: 01905 797989 - f: 01905 774296 | ©Duomo (UK) Ltd. 2007
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