Bacharach 50 User Manual

CO
SENSOR

GASKET

FILTER

WARNING!

Remove jumper-wire
(if installed) from pins
before installation

3. Push the Calibration Cup over the sensor housing.

4. Attach a CO Span Gas Cylinder to the regulator.
Then apply span gas to the sensor by adjusting the
regulator knob for a fl ow rate of 2 SCFH.

5. Allow span gas to fl ow until the displayed reading
stabilizes – approx. 3 minutes. Then, using Calibra­tion Tool 0006-9453 (supplied in Calibration Tool /
Cup Kit 0019-3242), turn the Span Adjust poten­tiometer until the displayed reading matches the
concentration stamped on the Span Gas Cylinder.

6. Calibration is now complete. Turn off the Regulator
and remove the calibration equipment.

Maintenance

Battery Replacement

Remove slotted screw from rear
of instrument; then lift off front
case.

Replace 9V Alkaline battery
(Duracell MN1604 or equiv.) in
location shown in Figure 3; then
reinstall front case.

Sensor Replacement

The sensor needs replaced when
it can no longer be calibrated to the Span Gas Cylinder
value using the Span Adjust potentiometer, or if it no
longer responds to a CO source.

1. See Figure 4. Remove the screw from the rear of the
instrument; then lift off the front case and remove
the printed circuit board assembly.

2. Unplug the old sensor and remove its gasket. Dis­card both items properly.

3. Inspect the sensor fi lter. Replace the fi lter if it has
become contaminated with dirt.

- 5 - - 6 -

Figure 3. Battery

Location

4. Remove wire-jumper (if installed) from pins of new
sensor; plug in sensor and install the new gasket
supplied; then reassemble the instrument.

5. Wait 30 minutes; then calibrate the new sensor.

Figure 4. Sensor Installation

Replacement Parts

Item Part No.

CO Sensor and Gasket .................................... 0019-7061

Filter ................................................................ 0019-3244

Accessories

Item Part No.

Calibration Kit ................................................ 0024-7059

Calibration Tool / Cup Kit .............................. 0019-3242

Span Gas Cylinder, 100 ppm CO in air ......... 0051-1994

Zero Gas Cylinder, 20.9% O2 in Nitrogen ...... 0051-7131

Bacharach Service Center

Replacement parts and accessories can be obtained by
contacting the following Bacharach Service Center:

Bacharach, Inc., 621 Hunt Valley Circle
New Kensington, PA 15068
Phone: [phone] • FAX: [phone]

Instruction 0019-9201

Rev.4 – May 2010

®

Sni t Model 50

Carbon Monoxide Analyzer

Introduction

Designed for HVAC professionals and utility person­nel, the Snifi t Model 50 Analyzer is ideal for measuring
low levels of CO in ambient air such as in rooms and
garages, or around registers, furnaces, stoves, water
heaters, and other types of combustion appliances.
The Snifi t samples the surrounding air and shows the
detected concentration of CO on its Liquid Crystal Dis­play. The Snifi t is not intended to be used in fl ue gases
or in temperatures exceeding 104 °F (40 °C).

Features

• Measures and displays 0 to 1999 ppm CO in room air

• Sensitive CO sensor will last up to 2 years

• Backlight for viewing in dark areas

• Compact pocket size

• Low battery indication

• Manual zero adjust

• Factory calibrated on 100 ppm CO

• Simple fi eld calibration

• Auto power-off after 35 minutes

• Single 9V battery (included) provides at least
1500 hours of operation

621 Hunt Valley Circle, New Kensington, PA 15068

Ph: 724-334-5000 • Fax: [phone] • Toll Free: 800-736-4666

Website: www.mybacharach.com • E-mail: [e-mail]

Printed in U.S.A. ® Registered trademarks

Bacharach, Inc.

MO N OXID E ANALYZER MONO XIDE ANALYZER

ppm CO

CARBONCARBON

Snif it

model 50model 50

BacklightOnOff

Span Adjust

-Power-

ZERO

ADJUST

(Recessed)

SPAN
ADJUST
POT.

BACKLIGHT

ON/OFF

POWER ON

POWER OFF

DISPLAY

LO BAT

LOW

BATTERY

INDICATION

1

234

Parts Shown:

1. CO Span Gas Cylinder, 51-1994

2. Regulator, 03-4318*

3. Tubing, 03-6351*

4. Flowmeter, 06-6163*

5. Calibration Cup Assembly, 23-2156**
* Part of Calibration Kit 24-7059

** Part of Tool / Cup Kit 19-3242

5

PUSH CALIBRATION CUP
OVER SENSOR HOUSING

LO BAT

Specifi cations

Gas Monitored ............. Carbon Monoxide (CO)

Range ........................... 0 to 1999 ppm

Resolution .................... 1 ppm

Accuracy ......................± (5% of reading + 5 ppm)

Response ...................... 30 sec. to 90% of fi nal value

Power ........................... 9V battery

Battery Life .................1500 hours minimum

Temperature Range ....32 to 104 °F (0 to 40 °C)

Case Material .............. High impact plastic

Weight .......................... 0.25 lb (0.11 kg) without battery

Dimensions .................. 5.5" L x 2.0" W x 1.6" H

(140 x 51 x 41 mm)

Operation

Turning the Snifi t
On & Off

The Snifi t is turned on
and off by pressing the

Power On and Power
Off buttons, respec-

tively. If the instru­ment is not manually
turned off, it will au­tomatically shut itself
off after approximately
35 minutes.

Zeroing the
Sensor

Turn on the Snifi t and allow the displayed reading to
stabilize before proceeding – approximately 30 seconds.
Then with the instrument sampling fresh air (air that
is free of CO), use a screwdriver to adjust the Zero
Adjust potentiometer at the top of the instrument for a
reading of 0 ±1 ppm.

- 2 -

Figure 1. Snifi t 50

If you’re not sure about the quality of the surrounding
air, you can apply a blend of Oxygen/Nitrogen gas to
the sensor as described under Calibration.

If rapid temperature changes are encountered (such
as from freezing to room temperatures) during the
operation of the analyzer, the operator must allow the
analyzer to stabilize at the ambient temperature for at
least 2 minutes before taking a measurement.

Checking for CO

Important! Ensure that the sensor grille at the rear of
the instrument is unobstructed and open to the atmo­sphere. A quick instrument check can be performed by
allowing the smoke of a blown-out match to enter into
the sensor grille. This should cause the indicated CO
level to increase.

After zeroing the Snifi t, simply hold the instrument in
the area that you suspect the presence of CO gas. If CO
is present, the instrument will indicate the concentrA­tion of CO in ppm on its display.

For more extensive CO investigations and testing in
areas of higher temperatures, the Monoxor® II is the
preferred instrument.

Backlight

Pressing the Backlight button will illuminate the
display for a period of 8 minutes, or until it is manually
turned off by again pressing the Backlight button.

Overrange

If the CO level exceeds 1999 ppm, the
displayed reading is replaced by the
number “1”.

Low Battery

When the Snifi t’s 9V battery is nearing
the end of its useful life, LO BAT will

- 3 -

appear in the upper left hand corner of the display.
Although you can continue using the instrument under
this condition, you should replace the battery as soon
as possible to ensure accurate CO readings.

Figure 2. Calibration Equipment Setup

Calibration

Important! For accurate Snifi t operation, calibration
every 6 months is recommended.

To calibrate the CO sensor, you will need the equip­ment listed under Accessories. Note that the Zero Gas
Cylinder is needed only if you’re unsure about the qual­ity of the surrounding air for zeroing purpose.

Calibrate the sensor to a known concentration of CO
gas as follows:

1. Assemble the calibration equipment per Figure 2.

2. Zero the instrument as previously described under

Zeroing the Sensor.

If necessary, you can use the calibration cup to apply

a blend of Oxygen/Nitrogen gas directly over the sen­sor by attaching a zero gas cylinder to the regulator
and adjusting the regulator knob for a fl ow rate of 2
SCFH.

- 4 -