2B Technologies 211 User manual

Portable N2O Source Manual Rev. B-2
0
Portable
N2O Source
For use with the
Model 211 Scrubberless Ozone Monitor and
Model 408 NO Calibration Source
© Copyright 2017, 2B Technologies, Inc.
All rights reserved.
Technical Support:
www.twobtech.com/techsupport
[email protected]
[phone]

Portable N2O Source Manual Rev. B-2
1
PRINTING HISTORY
This manual covers the Portable N2O Source, which is used with the Model 211
Ozone Monitor and the Model 408 NO Calibration Source. New editions of this manual
are complete revisions that reflect updates to the instrument itself, as well as
clarifications, additions and other modifications of the text.
Revision A.............................................................................................................. 2008
Revision B............................................................................................September 2016
Revision B-2..........................................................................................December 2017
(Clarifications regarding the use of different sizes of N2O cartridges; other minor edits.)
1. WARNINGS
Nitrous oxide (N2O) is supplied by a cartridge containing liquid N2O having a vapor
pressure inside the cartridge of 58.5 bar at 20°C. These cartridges are the same or
similar to ones sold as a consumer product for producing whipped cream. Nitrous
oxide or “laughing gas” is also used as a general anesthetic at concentrations up to
50% and is thus well tolerated by humans. There are no known toxicological effects
of N2O other than asphyxiation at extremely highly concentrations due to exclusion of
oxygen. N2O is not itself combustible, but it strongly supports combustion of organic
materials and reducing agents. Contact with liquid N2O can cause frost bite due to
cooling as the liquid rapidly evaporates. If an N2O cartridge is punctured outside the
piercing device/regulator, the cartridge will act as a “rocket.” However, the N2O
cartridges are commonly used consumer products available commercially and are
safe to handle if the procedures below are followed.
2. INSTALLATION
The Portable N2O Source is a standard feature of the Model 408 NO Calibration
Source and the Model 211 Scrubberless Ozone Monitor. A piercing device is used to
open disposable liquid N2O cartridges that are loaded in the cartridge cup, and an
integrated pressure regulator drops the pressure before delivering N2O (nitrous oxide)
to the instrument. A pressure gauge shows the pressure inside the cartridge, where a
drop in pressure (<~600 psi) indicates that the cartridge is almost empty. Either 8-
gram or 16-gram N2O cartridges may be used.

Portable N2O Source Manual Rev. B-2
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Figure 1. Diagram of the Portable N2O Source and mounting hardware.
To install the Portable N2O Source follow the following steps:
1) If there is no regulator mount on the instrument, first install the mount.
Model 211: If you have a newer instrument that has a regulator mount on the back
panel, proceed to Step 2. Otherwise, a new back panel will need to be requested
from 2B Tech and installed. Remove the top and bottom cover first and disconnect
all connections to the back panel. Taking a photo of the connections to the back
panel is a good idea to help ensure that the connections are remade correctly after
installation of a new back panel. Transfer all the components on the old back
panel to the new one. Mount the regulator mount to the back panel using the two
#10 pan head screws and split locking washers supplied with the Portable N2O
Source. Install the back panel on the instrument and install the top and bottom
panels.
N2O outlet (1/8” barb)
Pressure regulator
On/off valve (black knob)
Inlet pressure gauge
Two #10-32x1/2” Phillips head
screws with split washers
Regulator mount
One #10-32x1” socket cap screw with
flat washer
Removable cartridge cup to hold
disposable N2O cartridges. A
removable insert enables the use of
either 8-g or 16-gram cartridges.

Portable N2O Source Manual Rev. B-2
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Figure 2. Diagram of the Portable N2O Source mounted on a Model 211.
Model 408: If you have a newer instrument that has a regulator mount on the left
side panel, proceed to Step 2. Otherwise, a new left side panel with the correct
mounting holes will need to be requested from 2B Tech and installed. Remove all
of the screws around the enclosure front and back panels, including the screws on
the front bezel. Remove the left panel while keeping the top and bottom panels of
the instrument from sliding. Install the regulator mount on the left panel using the
two #10 pan head screws and split locking washer supplied with the Portable N2O
Source. Install the left panel on the instrument and install all of the screws at the
front and back panels of the enclosure.
Figure 3. Diagram of the Portable N2O Source mounted on a Model 408.
2) Loosen the single #10 socket cap screw (see Figure 1) to allow the regulator
assembly to slide into the mount.
3) Slide the regulator assembly into the mount from the top. Position the regulator
assembly so that the mount is centered on the top part of the piercing device,
not the black cartridge cup (see Figure 4). Tighten the #10 socket cap screw to
secure the assembly in the mount.

Portable N2O Source Manual Rev. B-2
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4) Connect the outlet of the regulator to the N2O inlet of the instrument.
Figure 4. Diagram of the N2O source properly installed in the mount.
3. OPERATION
Please read all the following information before attempting to use the Portable N2O
Source. For assistance, please call 2B Technologies at [phone] or email us at
[email protected].
Shipping Box Contents
Open the shipping box and verify that it contains the following:
1. Piercing device with integrated pressure regulator and removable insert
2. Regulator mount
3. Two #10-32x1/2” Phillips head screws with split washers
4. One #10-32x1” socket cap screw with flat washer
5. Connecting tubing to instrument.
If anything is missing or obviously damaged, contact 2B Technologies immediately.
Position top of regulator assembly so
that the mount clamps down in the
area indicated with arrows.

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Description
Nitrous oxide is supplied to the instrument by means of N2O cartridges. Each
cartridge contains ~16 g or~ 8 g of liquid N2O. When using the Portable N2O Source
with the Model 211 Scrubberless Ozone Monitor, the cartridges will supply a gas flow
of N2O of 13 mL/min for ~8 hours (16-g cartridge) or 4 hours (8-g cartridge). For the
Model 408 NO Calibration Source, the cartridges will supply a gas flow of N2O of 40-
60 mL/min and provide an operating time of ~2 hours (16-g cartridge) or ~1 hour (8-g
cartridge). The pressure inside the cartridge remains nearly constant as N2O
evaporates and flows out of the cartridge. The evaporation of N2O causes the N2O
cartridge to cool, which, in turn, slightly reduces the internal pressure of ~600 psi.
Installation of N2O Cartridges
1) Make sure that any cartridge already installed in the assembly is empty by
checking that the reading on the pressure gauge is below 50 psi with the on/off
valve open. To make sure the valve is open, check that the knob cannot be
turned clockwise any further. Do not tighten the knob more than hand-tight.
2) Close the on/off valve by rotating the knob clockwise until you feel the knob
stop turning.
3) Unscrew the cartridge cup from the assembly. Do not completely remove the
cartridge cup until you are certain that any residual N2O gas has escaped. If
you hear a hissing sound, N2O is escaping. Once all the N2O has been vented,
completely remove the cartridge cup and remove the empty cartridge. The
cartridges are made of steel and may be recycled.
4) Insert a new cartridge into the cartridge cup with the narrow neck of the
cartridge pointed upward.
If using an 8-g N2O cartridge, the removable insert should be left in place in
the bottom of the black cartridge holder. If using a 16-g cartridge, slide the
insert out of the black cartridge holder.
5) Reattach the cartridge cup to the piercing device. As you screw the cup onto
the piercing device, the cartridge seal will be punctured, and as you continue to
Warning: If an N2O cartridge is punctured outside the piercing
device/regulator, liquid N2O can escape, and if it evaporates on skin it will
cause frost bite. The cartridge will also act as a “rocket” if the seal is
punctured outside the piercing device/regulator. However, the N2O
cartridges are commonly used consumer products available commercially
and are safe to handle if the procedure below is followed.

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rotate the cup a seal will be made. You should rotate the cup quickly after
puncturing the cartridge to minimize loss of N2O gas. Do not tighten the
cartridge cup more than hand-tight so that it is not difficult to remove the cup
later.
Operation
1) When not using the Portable N2O Source, keep the on/off valve closed (knob
turned completely clockwise).
2) To use the Portable N2O Source, check that there is tubing connecting the
source to the instrument and then open the on/off valve by turning the knob
completely counter-clockwise. Use only moderate hand force to loosen the
knob (do not force with tools).
3) The pressure gauge will read ~600 psi, until the liquid N2O in the cartridge is
exhausted. Then the pressure will rapidly fall off.
4) To stop using the N2O source, close the on/off valve by turning the knob
completely clockwise. Do not tighten the knob more than hand-tight.