Manual

The Model 450A-1 Digital Pocket Size Carbon Monoxide Meter measures the
ambient concentration of carbon monoxide (CO) in the environment and displays
the measurement on the two line digital LCD screen. Besides the measurement,
the maximum recorded CO value since the last reset is shown. An audible carbon
monoxide alarm gives warning of CO levels above 25 ppm. For viewing in poorly
lit environments, the built-in back light brightens the display. Model 450A-1
includes soft carrying case with belt loop, wrist strap, and three AAA batteries.
OPERATING INSTRUCTIONS
Power On / Off
Press the button to turn the meter on or off.
Upon turning on the unit, the Model 450A-1 will go through a self test procedure.
The alarm value and the current ambient temperature will blink on the screen. The
self-test will be completed in approximately 15 seconds with a short beep.
Setting Temperature Units
To switch temperature units, press the button for more than 1 second during
self-test.
Backlight
The backlight can be turned on at anytime during the operation of the meter. Press
the button momentarily, to activate backlight. Press again to turn off backlight.
Alarm Setting
The audible alarm set point is pre-set to 25 ppm CO. The alarm value can be
adjusted by:
• Powering the Model 450A-1 off. Press and hold the button as the possible set
point values are displayed.
• Once the desired set point value appears, let go of the button. Possible alarm
values are 0, 25, 30, 35, 45, 50, 70, 100, and 200 ppm.
• The meter will return to self-test after the value is selected.
Model 450A-1 Digital Pocket Size Carbon Monoxide Meter
Specifications - Installation and Operating Instructions
Bulletin TE-450A
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]
SPECIFICATIONS
Range: 0 to 999 ppm.
Accuracy (at 20 ±5°C, 50 ±20% RH): ±20% @ 0 to 100 ppm; ±15% @ 100 to
500 ppm.
Resolution: 1 ppm.
Display: Dual digital LCD display.
Response Time: Less than 60 seconds.
Sensor: Electrochemical carbon monoxide sensor.
Ambient Operating Temperature: -10 to 60°C (14 to 140°F).
Operating Humidity (Non-Condensing): 5 to 99% RH.
Power Requirements: (3) AAA alkaline batteries, included, user replaceable.
Battery Life: 250 hours with backlight off; 35 hours with backlight on.
Alarms: Audible, preset at 25 ppm.
Weight: 4.23 oz (120 g).
Agency Approval: CE.
Resetting Max CO Level
The maximum CO level detected will be displayed on the lower line of the display.
It can be reset by pushing and holding the button for two seconds while in
normal operation.
Automatic Power Off (Sleep Mode)
The instrument will shut off automatically after 15 minutes if no buttons are
pressed. The meter will NOT turn off during calibration mode.
BATTERY REPLACEMENT
The Digital Pocket Size Carbon Monoxide Meter incorporates a visual low battery
indication. When the “Low battery symbol” appears, the 3 AAA alkaline batteries
need to be replaced. Another sign that the batteries need to be replaced is when
the thermometer fails to power on.
To Replace the Battery:
1. Make sure the unit is powered off.
2. Remove the battery cover.
3. Lay face down on a clean, flat surface.
4. Replace batteries, taking note of the indicated polarity.
5. Replace the battery cover.
645/64
[170.43]
633/64
[165.48]
R
ange: 0-999ppm 450A-1
1
3/32
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27.94]
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45/64
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43.26]
• Recovery time is needed when the meter has been exposed
to high levels of CO and the alarm has gone off. The longer
the exposure, the longer recovery time needed.
• Meter must be kept from electromagnetic interference. Exposure may cause
unreliable readings.
• Self-test after power on is required to test the sensor and circuit condition.
WARNING
It is recommended that the Model 450A-1 be turned on in a area
free of CO to avoid self test failures due to high CO
concentrations.
NOTICE
Failing to turn the meter off may result in malfunction of the unit.
Dispose of used batteries promptly and keep away from
children.
NOTICE