Dwyer Instruments 450 Series Operation and maintenance manual

Series 450 Carbon Monoxide Monitor
Instructions and Operation
SPECIFICATIONS
Range: 0-2000 PPM.
Resolution: 1 PPM.
Accuracy: (using 200 PPM calibration gas)
±3% of reading ± the accuracy of the cali-
bration gas, at the time of calibration.
Response Time: <30 seconds to 90% of
reading.
Operating Temperature: 32° to 104°F
( 0° to 40°C).
Humidity Conditions: 0-90% Relative
Humidity Non Condensing.
Adjustments: Zero and Span via keypad.
Power*: 9V Battery.
Battery Life: 500 hours typical
Case Material: Anodized Aluminum with
plastic end caps.
Dimensions: 6.8˝ L x 2.8˝ W x 0.9˝ D
except add 0.5˝ D for sensor cover.
(172.7 x 71.1 x 22.9 mm) (12.7mm).
Sensor Type: Field replaceable
Electrochemical Cell.
Sensor Life: 2 years minimum.
Alarms: 2 Alarms, with audible and visual.
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]
Lit-By Fax: [phone]
replace the endcap. Note that the endcap will
only fit one way because the holes are slightly
off-center. Place the “Z” shaped wrist strap clip
in one of the screw recesses and replace the
screw. Do not overtighten. Attach the wrist
strap to the clip.
Use only 9 Volt alkaline type batteries such as
Duracell®MN1604, or Eveready®522, or
equivalent. Zinc-carbon types, often labeled
Heavy-Duty are not recommended because of
their shorter life and increased potential for
leakage. Alkaline batteries are a better value
because they typically last up to three times
longer in this device.
Duracell®is a registered trademark of Duracell USA, a division of
Duracell Inc.
Eveready® is a registered trademark of Eveready Battery Company Inc.
The Series 450 CO Monitor measures car-
bon monoxide from levels 0 to 2000 PPM. The
unit is equipped with audible and visual indica-
tors of CO concentration. The beacon indica-
tor flashes in correspondence to the level of
CO detected in the air. Perfect for HVAC appli-
cations such as servicing heaters, furnaces,
appliances and for general building inspection.
BATTERY INSTALLATION
Remove two screws holding the bottom end-
cap labeled BATTERY in place and remove it.
Connect the battery to the enclosed battery
clip observing correct polarity. Insert the bat-
tery in the case. Be careful not to trap the
wires between the case or foam pad, which
retains the battery. This could make it difficult
to install the battery or remove it later for
replacement. Be sure the rubber gasket is
properly seated in the gasket channel and
Bulletin D-25
*NOTE: This instrument is shipped with a new 9V bat-
tery. However, there is a protective plastic cap installed on
the battery terminals. This cap must be removed and the
battery connected to the battery terminal before the instru-
ment will function.
d-25small 11/5/02 3:02 PM Page 1

LOW BATTERY INDICATION
When the 9V battery is reaching the end of it’s life, the “LOW BAT” indicator
on the display will turn on.
FUNCTIONS ACCESSED DIRECTLY THROUGH KEYPAD
On Off Operation:
Pressing turns power on, pressing again turns power off. The unit will
automatically shut off if there is no activity for 20 minutes. To defeat the auto-
matic shut off, when turning the unit on press and hold the key down
and then press
Display Backlight:
Press to turn the backlight on, again to turn the backlight off. The back-
light will automatically turn off after 2 minutes to conserve battery power.
Display Hold:
Pressing and releasing will freeze the display and illuminate the “HOLD”
annunciator.
Pressing again will extinguish the “HOLD” annunciator and the display
will again be updated.
To Store a Reading In Memory:
Up to 25 CO readings may be stored in memory. Pressing will store
the presently displayed value in memory. The active memory location will be
displayed in the lower left, starting initially with “1”. The MEM descriptor will
turn on any time there are any values stored in memory.
m
MEM
PPM
CO
Memory Location
HOLD
PPM
CO
“HOLD”
Annunciator
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
2
d-25small 11/5/02 3:02 PM Page 2

As each reading is saved, the memory location is advanced to the next location.
When 25 readings are stored in the memory location, it will begin at “1” again.
After a reading is stored, the display will return to the home position.
FUNCTIONS ACCESSED THROUGH THE MENU
How to Use the Menu:
To access the menu, press to enter the menu mode. Continue pressing
until the desired menu item is displayed. When the instrument is in the
menu mode, the key will function as the “INCREMENT” key, and the
key will function as the “DECREMENT” key.
When the desired menu item is displayed, use the and keys to
modify the menu item to the desired value, then press to store the value
in memory. If the key is not pressed, the original menu value will be retained
in memory and not changed. To exit the menu, scroll to the home position. While
in the menu mode, if no activity is detected for 30 seconds, the display will auto-
matically return to the home position.
Reading a Stored Value:
Index the menu until the lower display reads . The lower left display shows
the active memory location, upper display shows the memory value. Use
and to sequence through the memory locations. To clear the
memory, press and hold the key for five seconds while in this menu loca-
tion.
Reading the Peak Value:
The Peak feature stores the highest reading the monitor has measured since the
last reset or Power On. At Power On PEA is reset to the present reading. To view
the peak value, index the menu until the lower left display reads PEA.
When PEA is displayed, pressing the key will reset the value to the pres-
ent CO value.
MEM
PPM
CO
Stored Value
“ST” = storage
Memory
Storage Location
“MEM” Descriptor
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
3
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
d-25small 11/5/02 3:02 PM Page 3

ALARMS
The monitor is equipped with two alarms. Alarm 1 is the lower alarm value, and
Alarm 2 is the higher alarm value. Alarm 1 is factory set 35 PPM, and Alarm 2 is
factory set to 200 PPM. When the displayed value reaches the alarm setting, the
appropriate alarm descriptor will turn on.
The lowest setting of Alarm 1 is limited to 35 PPM to avoid false alarms. Alarm
2 must be set a minimum of 100 PPM higher than Alarm 1.
To change an alarm setting, index the menu until the lower left display reads AL
1 or AL 2 and use the keys to set the desired alarm setting.
Press the key to store the setting.
The monitor is equipped with both audio and visual alarms. When Alarm 1 is
reached, the audio alarm will beep and the visual alarm will flash. The speed of
the audio beeping and visual flashing will increase until Alarm 2 is reached. At
this point the audio and visual alarms will be on continuously. The Audio and
Visual alarms are factory set to be on. To turn the Visual alarm off, index the
menu until ALF (Alarm Flasher) is displayed in the lower left display. Then use the
key to turn the Visual alarm off. The upper display will read OFF. Then
press to store the change. To turn the Visual alarm back on, press the
key, then press to store the change. The Audio alarm may be
turned off or on in the same way as the Visual alarm by indexing the menu until
the lower left display reads ALb (Alarm Beeper).
Zero Adjustment:
Place the instrument in a CO free environment. Allow the instrument to stabilize
at least three minutes. The instrument should read Ø PPM. If it reads >10 PPM,
the sensor is bad and should be replaced. If it reads 1 to 9 PPM, the zero may
be adjusted as follows:
1. Index the menu to CAL0.
2. Press the and keys simultaneously. Index the menu back to the
home position. The display should now read Ø PPM.
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
4
d-25small 11/5/02 3:02 PM Page 4

CALIBRATION
IMPORTANT NOTE: Electrochemical CO sensors slowly lose sensitivity over
time. A quick “bump test” should be performed with CO gas before each usage
to ensure proper instrument performance. It is also recommended to perform
a calibration at four month intervals to guarantee proper operation. A replace-
ment sensor should be installed if the unit can no longer be calibrated. In order
to perform a calibration, a calibration kit is required. This is available from Dwyer
Instruments, see below to order.
CALIBRATION ACCESSORIES
A-450-1 Calibration Kit with Regulator: Includes case, Series 450 Handheld
Carbon Monoxide Monitor, regulator, tubing and A-450-2 Calibration Adapter.
For use with 17 liter gas tank. The regulator has a fixed flow rate of 0.5 L/min.
If a different Calibration Kit is used, a flow meter is required that can verify set-
ting the flow rate correctly to 0.5 L/min.
A-450-2 Calibration Adapter: Adapter connects the regulator to the sensor
cover on the back of the CO Monitor.
A-450-3 Replacement Sensor
A-450-4 Aspirator Kit: Includes aspirator bulb, adapter, tubing and probe.
A-450-5 Calibration Regulator Kit: without Series 450 Carbon Monoxide
Monitor (same as A-450-1 except without Series 450 Handheld Carbon
Monoxide Monitor.
CALIBRATION PROCEDURE
1. Zeroing the Instrument: It is important that the instrument is in an area with
zero concentration of CO gas. Turn the instrument on and allow it to stabilize for
three (3) minutes. Press the key until the display reads CAL0. The upper
display should read between 0 and 12. If the upper display reads above 12, the
sensor may be bad and should be replaced – refer to SENSOR REPLACE-
MENT. Press the and keys simultaneously. The display will momen-
tarily blink to show the value has been stored.
5
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
d-25small 11/5/02 3:02 PM Page 5

2. Refer to FIG. A, “Calibration Kit Setup”. Attach the regulator to the calibra-
tion gas cylinder (make sure the valve is closed). Attach the hose from the cal-
ibration adapter kit to the regulator, then place the adapter cap over the sen-
sor housing on the back of the instrument.
NOTE: The regulator used with the Dwyer Instruments Calibration Kit has a
fixed flow rate of 0.5 Liters/Minute. If a different calibration kit is used, make
sure the flow is set to approximately 0.5 Liters/Minute. A flow rate greater than
1 Liter/Minute will result in an inaccurate reading.
3. Span Calibration: Turn on the valve on the regulator and allow gas to flow
for at least three minutes. Press the key until the display reads CAL0.
Press and hold the and enter keys for five seconds until the lower dis-
play reads CAL1. Verify that the upper display reads between 125 and 400,
then press the and keys simultaneously. The display will blink to
show the calibration value has been stored. If the value is <125 or greater than
400, the sensor is bad needs to be replaced. Refer to “SENSOR REPLACE-
MENT”.
4. Index the menu back to the home position. The instrument should read 200
PPM +/- 2.
Push calibration adaptor
cap over sensor housing.
1. CALIBRATION
GAS CYLINDER - 200 PPM CO/AIR
2. REGULATOR:
CALIBRATION KIT A-450-1
3. ADAPTER:
CALIBRATION KIT A-450-1
Adapter also available
seperately: Part Number A-450-2
Fig. A
6
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
HOLD
STORE
ENTER
ON
OFF
BACKLIGHT
INDEX
d-25small 11/5/02 3:02 PM Page 6

GASKET CAP MTG. SCREWS (2)
CO SENSOR: A-450-3
WARNING!
Remove and discard spring
from pins before installation.
CO MONITOR 450 SIDE VIEW CO MONITOR 450 REAR VIEW
SENSOR REPLACEMENT
A replacement CO sensor is available from Dwyer Instruments.
Order part number: A-450-3
Replacing the sensor
1. Refer to FIG. B Remove the two MTG screws.
2. Carefully remove the sensor cap.
3. Remove and discard sensor.
4. Remove shorting wire spring from pins on new sensor.
5. Carefully install new sensor into instrument. Re-install cap and mounting
screws.
6. New sensors must be recalibrated. Wait a minimum of 30 minutes after
installing a new sensor before calibrating the instrument. The instrument has
internal temperature compensation and the sensor must be at the same tem-
perature as the instrument to calibrate properly.
GASKET CAP MTG. SCREWS (2)
CO SENSOR: A-450-3
WARNING!
Remove and discard spring
from pins before installation.
CO MONITOR 450 SIDE VIEW CO MONITOR 450 REAR VIEW
Fig. B
P
7
d-25small 11/5/02 3:02 PM Page 7

Date Notes
Bulletin D-25
SERIES 450 CALIBRATION LOG:
Calibrate once every 4 months/Replace sensor if unit can no longer be calibrated.
©Copyright 2002 Dwyer Instruments, Inc. Printed in U.S.A. 11/02 FR# 08-443193-00 Rev. 1
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]
Lit-By Fax: [phone]
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
_____________________________________________
d-25small 11/5/02 3:02 PM Page 8