AMI 111 User manual

Made in the USA
AMI
Oxygen Analyzer Manual
Model 111/111P
AMI, Costa Mesa, CA

AMI Analyzer Manual Contents i
Contents
Preface 1
Thank You 1
Caution 1
Address 1
Model 111/111P Oxygen Analyzer 2
Introduction 2
Features: 2
Data logging: 3
Sample conditioning: 3
Safety: 4
Sensor Warranty: 4
Instrument Warranty: 4
Installation and Operation 5
Receiving the analyzer 5
Charge the batteries: 5
Location: 5
Sample gas and electrical connections : 6
Interconnections: 7
Digital communications: 7
Sample connection: 7
Operation 8
General Description: 8
Front Panel Controls: 8
Flow Rate Adjustment: 8
Front panel LED: 8
Calibration (25% unit): 9
Calibration (111 or 111P with optional 95% range): 9
A note on analyzer linearity: 10
Atmospheric pressure effects: 10
Communication program: 11
Top section: 12
Analyzer Info Section: 12
Analyzer Setup Section: 12
Sensor Calibration Data: 13

AMI Analyzer Manual Contents ii
Data Logging 13
Variables: 15
Maintenance and troubleshooting 16
Maintenance: 16
Sensor Replacement: 16
Battery Replacement: 16
Troubleshooting 17
Specifications and Disclaimer 19
Specifications: 19
Disclaimer 20

AMI Analyzer Manual Preface 1
Preface
Thank You
For purchasing a state of the art oxygen analyzer. The 111 series of analyzers provide unmatched accuracy,
reliability and longevity among percent level oxygen analyzers. They use an innovative zirconium oxide
sensor that is highly stable, and minimally responsive to pressure changes, thus making the analyzer one of
the few not to be affected by barometric pressure changes.
The standard model, called 111, is intended for positive pressure samples up to 100psig; the 111P adds a
pump that allows it to operate on low pressure and vacuum samples from plus 10psig to 15 inches of
mercury vacuum (7.5psia). Both analyzers are battery powered, but may be operated indefinitely from the
wall charger supplied. They are CE marked, meaning that they meet the European (and thus by default the
American) standards for EMI immunity and safety in a general purpose area. They are not designed for use
with flammable samples or in a hazardous area.
Oxygen analysis can be a problematical area for people with no experience in it – and AMI is always happy
to help you if you run into any problems. Please feel free to call at any time for help.
Caution
Read and understand this manual fully before attempting to use the instrument. In particular understand
the hazards associated with using flammable or poisonous gases.
Address
Advanced Micro Instruments.
225 Paularino Avenue
Costa Mesa, CA 92626
[phone]
www.AMIO2.com
The unit meets the requirements of EN 61326-1 2006 and EN 61010-1. It is therefore CE marked.
Last Revised: 08/31/2018

AMI Analyzer Manual Model 111/111P Oxygen Analyzer 2
Model 111/111P Oxygen Analyzer
Introduction
The Advanced Micro Instruments Model 111 and 111P provide the latest in high precision percentage
oxygen measurement in the range of 0.1% to 25% (or optionally, 50% and 95%). The Model 111 and 111P
incorporate a state of the art Zirconium Oxide sensor that provides unprecedented accuracy and stability,
while retaining the traditional AMI features and ease of use. The analyzers are portable and battery
powered, however the sensor uses quite a lot of power and so the battery life is shorter than that of wet
electrochemical analyzers, particularly if the pump is used. It has no analog output but instead records data
electronically for subsequent download to a PC.
Features:
Single measurement range; four datalog ranges selectable.
High resolution 3 ½ digit LCD
RFI protected
Data logger
USB virtual comport communication for advanced features
Power requirements: 115/230VAC to 12VDC battery charger
Low minimum detection limit 0.01% oxygen (25% version)
Excellent repeatability and stability
Extended operating temperature range to 130°F
Fast upscale/downscale response times
Long life sensor, 10 year life expectancy
Unaffected by changes in flow rate from 0.1 to 2.0 SCFH
Compact portable
Meets UL Requirements (EN 61326-1 2006 and EN 61010-1). CE Marked for European Use.
2 year warranty for analyzer parts and labor
2 year sensor warranty

AMI Analyzer Manual Model 111/111P Oxygen Analyzer 3
Data logging:
The unit contains a real-time clock and 32K of non-volatile memory that provide a data logging function to
be accessed by the AMI User Interface Program. It will automatically log readings and the time and date at
intervals for subsequent downloading into a computer.
It records the average reading over a user-selectable period (in minutes), and after every 32 readings it
records the time and date so that the user may reconstruct the data accurately. If logging is turned off, and
then restarted, it will continue logging where it left off (starting with a new time and date stamp) – it won’t
overwrite the earlier data until it reaches the end of its memory.
Using the User Interface program supplied by AMI, the data may be downloaded into a “CSV” file for
manipulation in Excel™ or similar spreadsheet programs, and the logging can be restarted at the beginning
again. The internal time and clock may also be set, as well as a label to distinguish data from this analyzer
from others.
As an example, if the time interval is set for 1 minute, the unit will average the readings for one minute and
then store the average. Every 32 minutes it will also store the current date and time. It will continue doing
this for about 20,000 data points, i.e. about two weeks, assuming it is left plugged in to its charger! After
that time it will start writing over its earliest data.
Sample conditioning:
The model 111 is intended to use a positive pressure sample. The sample should be free of liquids, and
dust. It must be free of combustible material, since the sensor will oxidize anything combustible, reducing
the oxygen reading by the amount it took to burn up the contaminant. It is intended to operate with
nitrogen as the background gas – high concentrations of other gases may be problematical, mostly because
any significant change in thermal conductivity will either overheat or cool off the sensor. Generally
speaking, up to 10% of any non-flammable gas is not a problem, but higher concentrations (other than
nitrogen) may be. Please contact the factory for details if this should apply to you.
The analyzer does not respond to barometric pressure changes, unlike conventional oxygen analyzers.
Optional versions are available that can measure oxygen up to 50% or 95%.
The model 111P is equipped with a long-life pump, capable of drawing a sample through the sensor from an
ambient pressure source, or vacuums down to 15”Hg. It will also operate at inlet pressures up to 10psig.
The pump does draw more current than the rest of the analyzer, so the battery life is considerably shorter if
you run the pump all the time; however like the standard unit it will operate indefinitely if plugged into its
charger.
Using the AMI user interface program, the unit can be programmed to switch off the pump after a few
minutes of operation, though by default it will run continuously. The LED on the front panel wi ll change
from green to blue when the pump is in use. If the batteries are low, the pump will only run for five
seconds. Sometimes when the batteries are getting low, the increased current draw of the pump will

AMI Analyzer Manual Model 111/111P Oxygen Analyzer 4
reduce the battery voltage and thus turn the pump off – in this case both the red and blue LED’s will come
on while the pump is running.
Safety:
A component of the sensor operates internally at a high temperature and will ignite any flammable gas
mixture it sees. Do not use this analyzer with flammable gases of any kind. (Note, the analyzer itself runs
at ambient temperature).
Oxygen sensor:
The Model 111’s Zirconium oxide sensor produces an output current in proportion to the amount of oxygen
present, and has virtually zero output in the absence of oxygen, thus avoiding any requirement to zero the
analyzer. The span calibration may be performed using a standard span gas or oil-free compressed air. The
sensor is so stable that span calibrations are only necessary once or twice a year. Unlike conventional
sensors, the sensor does not age when it is not powered.
WARNING
All zirconium oxide sensors operate at high temperature, and are unsuitable for
measuring flammable gases. Any hydrocarbon gas will oxidize on the sensor, reducing
the oxygen reading by the amount of oxygen required to burn the hydrocarbons. DO
NOT USE THIS ANALYZER WITH FLAMMABLE OR EXPLOSIVE SAMPLES!
Sensor Warranty:
The sensor is warranted to operate for at least two years, with an expected life between five and ten years.
Instrument Warranty:
Any failure of material or workmanship will be repaired free of charge for a period of two years from the
original purchase (shipping date) of the instrument. AMI will also pay for one way shipment (back to the
user).
Any indication of abuse or tampering will void the warranty.

AMI Analyzer Manual Installation and Operation 5
Installation and Operation
Receiving the analyzer
When you receive the instrument, check the package for evidence of damage and if any is found, please
contact the shipper.
Charge the batteries:
Plug the wall adapter supplied into a suitable wall socket. The charger is a universal charger, and can b e
plugged into any voltage between 100 and 240 VAC. Plug the power jack into the back of the analyzer, and
allow it to sit overnight for at least 14 hours. The internal charging circuit will not allow the batteries to be
overcharged. The batteries in the model 111 will last for about 8 hours of continuous operation. In the
111P, they will last the same length of time if you don’t use the pump; the pump will drain them in about an
hour if you use it continuously. The unit is able to operate while the batteries are being charged. The
maximum voltage the power input can accept is 13VDC. Anything higher than this will damage the unit.
Location:
The unit is designed to be used in a general-purpose area. It is not suitable for use in a hazardous area or
with hazardous (explosive or flammable) gases. It may be operated either off its internal batteries or else
off the charger, in which case it will simultaneously operate and recharge itself.
Although the unit is RFI protected, do not to mount it close to sources of electrical interference such as
large transformers, motor start contactors, relays etc. Also avoid subjecting it to significant vibration.

AMI Analyzer Manual Installation and Operation 6
Figure 1. Outline Drawing
Sample gas and electrical connections:
The sensor is built into the analyzer, and does not need any separate installation. It is equipped with ¼”
compression fittings on the inlet.
The exhaust should be left open, or if desired, brought through a low restriction tube such as ¼” diameter
plastic tubing to a safe area.

AMI Analyzer Manual Installation and Operation 7
The only electrical connection, other than the battery charger input, is a USB connector suitable for use
with a standard USB type A to type B cable (such as is often supplied with a PC printer).
The unit is powered by its internal batteries but may also be powered as well as recharged by plugging in
the power adapter supplied to the socket on the rear of the unit.
Interconnections:
Digital communications:
The Model 111/111P is equipped with a USB connector on the back of its case. This may be used to access
data that has been logged by the built-in data logger, as well all the other features of the analyzer. These
include the calibration settings, linearity settings, heater settings and internal voltages.
Use a standard USB cable and software supplied by AMI to configure and download data.
NOTE: THE COMPUTER USED MUST MEET UL STANDARDS FOR ELECTRICAL SAFETY!
Sample connection:
This unit is designed to be used with ¼” tubing supplied by the user. As an option AMI can supply a special
flexible tubing accessory that avoids damage to fittings. It uses O ring sealed hand removable fittings. See
the accessory page below. Attach it to the analyzer using a suitable fitting. Adjust the flow with the
flowmeter valve to approximately 1 SCFH. After one to two minutes (depending on flow rate) the reading
will stabilize.
For the standard unit (model 111), make sure the inlet pressure is between 0.5psig and 100psig.
For the pump version (model 111P), make sure the inlet pressure is between +10psig and about 15” Hg
vacuum. Higher vacuums than this may damage the pump.
If the unit is plugged into its charger, it will run indefinitely.
For best response time and repeatability, take the reading at 1SCFH.
The sensor responds only minimally to barometric pressure changes – about 0.4% of reading for a 5psi
pressure change (which is equivalent to a change in elevation of about 12,000 ft!).
Its output is slightly reduced by the presence of CO2 – substituting 1% CO2 for an equivalent amount of
nitrogen in a gas mixture (i.e. air) will change the reading from 20.9% to 20.85%. Water vapor will also
reduce the reading but merely by diluting the oxygen, not by affecting the sensor. Saturated air at 110F
contains about 3% water vapor, so the oxygen reading will be reduced by 3% of 20.9% i.e. to 20.3% oxygen.

AMI Analyzer Manual Installation and Operation 8
Operation
General Description:
This analyzer is designed to be as simple to operate as possible. The analyzer displays the oxygen level in
appropriate units on the LCD, automatically adjusting its sensitivity as required. Please note that the sensor
takes about two minutes to warm up when the analyzer is turned on. During this time, the analyzer will at
first display 0% oxygen, and then the reading will climb up and overshoot before settling back down. Don’t
span it for at least ten minutes after it has warmed up as its reading may change by 0.1% oxygen over that
time. You can view the sample flow rate on the built-in flow meter, and adjust it with the needle valve on
the front of the analyzer.
Front Panel Controls:
The basic operation of the analyzer is controlled from its front panel. It has a series of tactile switches
marked On/Off, Span and (in the case of the 111P) Pump, and two up and down arrow switches.
Pressing the ON/Off switch will turn the unit on (if it is off) and off if it is on. Press and hold it for a second.
Note that the sensor will take the same two minutes to warm up no matter how quickly you turn it on again
after it has been turned off!
The Span button allows you to calibrate the unit. See the Calibration section below.
The analyzer has a security feature which may be enabled by the User Interface program. If enabled, the
span control will not have any effect. This may prevent an unauthorized person from changing the
calibration incorrectly.
Flow Rate Adjustment:
Use the valve on the bottom of the flow meter to control the flow rate. This is not critical, since the
analyzer is not sensitive to small pressure changes. The main effect is to change the response time – a slow
flow rate may take a while to refresh the gas at the sensor. Simply standardize on a particular flow rate
(typically 1 SCFH) and take all measurements at that value of flow.
Front panel LED:
There is a multi-color LED visible behind the little box with “Status” written on it. This LED changes color
depending on the operational state.
In normal operation, it will be green.
If the pump is running, and the batteries are charged, it will turn blue (this is not applicable for the 111
version).
When the batteries are low, it will turn red, and the pump in the 111P will not work for more than five
seconds.
When the unit is being recharged, and is turned on, both the red and green LED elements will turn on,
producing a yellowish effect.

AMI Analyzer Manual Installation and Operation 9
Calibration (25% unit):
1. (111P) Turn on the pump, and allow the analyzer to draw in clean air at 1SCFH.
2. (111P) Optional: connect to a span gas cylinder with the regulator set at 8 psig.
3. (111) allow clean air from an air compressor (with an oil filter) or span gas to flow through the
analyzer at 1SCFH. Make sure the source pressure is under 100psig, preferably 10psig.
4. Let the reading stabilize for approximately 2 minutes.
5. If the value shown by the analyzer is other than 20.9%, press the SPAN b utton.
6. Within 3 seconds, press the Up or Down arrow button and hold it.
7. When the reading has reached the desired level, release the button.
Once you let go of the SPAN button, after a few seconds the “SPAN” flag on the display will go out and the
unit will store the new span coefficient in its non-volatile memory
Note: It is possible to disable the calibration function with the AMI User Interface program. If it is not
apparently possible to change the calibration, you must reset the security condition to “All front panel
adjustments allowed” using the AMI user interface. Perform the calibration as above, and then change it
back to “No front panel adjustments allowed” when you are done.
Calibration (111 or 111P with optional 95% or 50% range):
WARNING
95% oxygen is a hazardous oxidizer! Use only components cleaned for oxygen service!
Use only a dual stage regulator with stainless steel diaphragms on the span gas tank!
1. (111P) Allow the analyzer to draw in 1SCFH of 95% (or 50%) oxygen with balance nitrogen span
gas. Make sure the cylinder regulator is set at 8 psig.
2. (111) Flow 95% (or 50%) oxygen with balance nitrogen at 1 SCFH. Make sure the source pressure
is no more than 10psig.
3. Let the reading stabilize for approximately 2 minutes.
4. If the value shown by the analyzer is other than 95% (or 50%), press the SPAN button.
5. Within 3 seconds, press the Up or Down arrow button and hold it.
6. When the reading has reached the desired level, release the button.

AMI Analyzer Manual Installation and Operation 10
A note on analyzer linearity:
Since the analyzer generates a relative measurement, it is not possible to characterize its linearity any
better than by using a series of primary standard gases to verify its performance. Since these gases are only
specified to be 1% accurate, we can’t specify the analyzer as being any better than that, hence the 1%
linearity spec. Experience indicates that in fact over many measurements we do better than 1%, but we
can’t guarantee it since there is no way of verifying that we really do so. For particular purposes, there are
software adjustments that we can make that provide specific curve changes so that we can exactly match
what a particular set of gases say, however these are by default left in their standard (linea r) position. If for
some reason you absolutely do have to match the analyzer to a set of standard gases, we can help you do
so using our User Interface software package. We do recommend against doing this save as a last resort.
Atmospheric pressure effects:
The sensor is not particularly sensitive to changes in ambient pressure – a 5psi ambient change will change
its reading by 0.4% of its value (i.e. 20.9% at 15psia will read about 20.8% at 10psia). Atmospheric pre ssure
changes are usually less than 1psi, so the error due to this will be unnoticeable. Greater changes will be
noticed from humidity effects when measuring air – at 110ºF you can have up to 3% humidity, which
effectively reduces the oxygen concentration by the same proportion, to 20.3%.
High oxygen level gas hazards:
High oxygen level gas such as 95% oxygen in nitrogen is a very strong oxidizing agent. Treat it as if it is pure
oxygen, and familiarize yourself with the rules for handling pure oxygen before attempting to use it. In
particular, all tubing used must be suitable for oxygen service, and if you are using a high pressure span gas
cylinder, you MUST use a dual stage regulator with stainless steel diaphragms on it. Any sudden failure of a
regulator may allow enough temperature rise through adiabatic compression to ignite virtually anything,
including stainless steel tubing and an AMI analyzer.

AMI Analyzer Manual Installation and Operation 11
Communication program:
Figure 2. User interface initial screen
Load the program into your laptop computer by putting the CD into its CD or DBVD drive, and following
instructions in the usual way. Make sure the analyzer is turned on and plugged into the computer using the
USB cable before running the program.
The program will come up, and once you click the “Port” button (next to the OPEN COMM button at the
top) will show a screen as above. Select the appropriate port, click “Open Com” and the program will
automatically select the appropriate baud rate and determine the kind of analyzer present. It will fill in the
relevant boxes and grey out the irrelevant ones.
The ports available will be shown. Depending on your particular computer, the port may be anything. If
there are more than one available, you may have to try them all until you get the one that works.
Note that if the analyzer loses power, you will have to restart the AMI program as the USB chip will have to
restart. This is why you have to turn the analyzer on before you run the program.

AMI Analyzer Manual Installation and Operation 12
Once the program has connected, it will automatically fill in the various boxes with values it gets from the
analyzer.
You can change values by writing in the new value and pressing ENTER (on the keyboard), or by c licking the
appropriate button or scroll button. The program will send the values down to the analyzer, and after a
little, read the value back to make sure it “took”. If it didn’t for some reason, the value will change back to
whatever the analyzer actually has. Don’t try to change many settings simultaneously, as the analyzer may
get confused. Give each one a second or so to take.
Top section:
This shows the version of the user interface, the user ID (which can be set as desired by clicking on it) and
the time and date.
Analyzer Info Section:
These boxes are populated by the program from data provided by the analyzer. (The 111 series of analyzers
do not have all the features supported by this program, so a number of these boxes will be greyed out).
The analyzer model code will be shown at the top of this section.
The current oxygen reading will be shown in the “Reading” text box. The span factor will be shown below
that.
The power supply voltage is shown in the box marked “Power”. The output range is shown – this is the
range over which the unit logs data - and also the security setting and the analyzer serial number.
Analyzer Setup Section:
First, set the desired output range. The logged data is stored as a percentage of this range.
Select the security level desired. You can choose between none, (a user can adjust any of the front panel
controls), span only (which is effectively the same as “none” for this analyzer), and full, in which case he can
look at the settings but not change any of them.
The alarm set points and the output calibration are irrelevant for this analyzer.

AMI Analyzer Manual Installation and Operation 13
Sensor Calibration Data:
This section shows information about the sensor. The Oxygen reading shown on the front panel, as well as
the upper left portion of this screen is repeated in this section, and can be adjusted by editing the span
factor in the box below, just as if the unit is calibrated via the front panel.
The sensor history is not supported by this analyzer, due to the special nature of the sensor used.
Data Logging
Figure 3. User interface datalog chart (ppm analyzer shown)
The program shows what the analyzer thinks is the current time and date, and also what your computer
thinks is the current time and date. You can send the computer time and date to the analyzer by clicking on
the “Set Analyzer Time” button. If you change the time and date, you may want to click the Clear Data
button so the software doesn’t get confused by later times being earlier than earlier times!
The analyzer logs data at a rate set by the “Datalog Interval” box. Typically this interval will be set to 1
minute. The unit is capable of storing about 21000 data points, corresponding in this case to 21000
minutes, or rather more than 14 days. Setting the interval to 4 minutes will allow it to store over two

AMI Analyzer Manual Installation and Operation 14
months of data. The oxygen reading is averaged for the logging period, and stored as a percentage of the
current output range, with a resolution of 1% of the output range. Every 32 data points, various internal
parameters including the time and date are stored as well. If the memory capacity is exceeded, the unit will
overwrite the oldest data and keep on storing data in a circular fashion so that always the most recent set
of data points can be retrieved.
Note that since the unit only stores the output range every 32 data points, if you change the output range
this won’t be recorded until the next time it stores this value, but the reading of course will change
immediately. This means that there will be up to 32 data points with apparently the wrong value stored.
We recommend that if you do change the output range you clear the data so that no confusion can arise.
You can download the stored data by pressing the “Download Data” button. It may take a couple of
minutes to get it all, and the progress of this process is shown in a color bar, in traditional Windows style,
though unlike most Windows programs the length of the bar does in fact correspond with the amount of
data already retrieved.
Once the data is retrieved, it will be displayed in tabular form. It is automatically saved as an Excel™
compatible “CSV” format for subsequent analysis, so when you press the graph button the program opens a
dialog box which allows you to graph any of the stored files – the latest one will of course be the most
recent one. Double click it and the graph will appear. In the graph display you can zoom into data by
clicking the “Zoom In” button, and zoom out by clicking the “Zoom out” button.
The analyzer can be left to overwrite the old data by itself, or else it can be told to start again at the
beginning by pressing the “Clear Data” button.
The chart shows the oxygen reading, and the average battery voltage.

AMI Analyzer Manual Installation and Operation 15
Figure 4. User interface Variables Screen
Variables:
This screen shows the internal operation of the analyzer, together with the operation of the communication
program. It allows you to interrogate the analyzer for a particular variable manually, but normally this is not
necessary. When the analyzer is first connected, the program will fill up all the variables in the list and will
then poll a subset of them regularly. If desired the “REFRESH” button will cause the program to update
every variable.
Mostly this screen is used for troubleshooting.

AMI Analyzer Manual Maintenance and troubleshooting 16
Maintenance and troubleshooting
Maintenance:
The AMI oxygen analyzer is virtually maintenance free other than for periodic calibration.
Sensor Replacement:
The sensor should last for many years. If the sensor expires you will have to return the analyzer back to the
factory.
Battery Replacement:
The NiCd batteries provided should last for many years, but as with all batteries they will die eventually. To
replace the batteries, follow these steps:
1. Remove the two front panel screws, and pull out the front panel. It won’t come out very far as it is
attached to many wires.
2. Disconnect the USB connector ribbon cable from the pc board.
3. If it is easier, unscrew the terminals holding the four sensor wires.
4. Remove the four socket head cap screws holding the battery bracket. These are located on the left
side of the unit.
5. Remove the battery bracket.
6. Locate the two wires leading from the batteries to the pc board, and unplug them.
7. Replace the entire assembly with a new one available from AMI.
8. If you removed the sensor wires, screw them back into the terminal block. Note the color code is
written on the back of the PC board next to the connectors.
9. Plug in any connectors you unplugged and replace the front panel. Charge (or recharge) the
batteries for 14 hours prior to using the unit.

AMI Analyzer Manual Maintenance and troubleshooting 17
Troubleshooting
Analyzer does not power up.
1. Plug the charger into it and verify that the green light on the back comes on.
2. Charge the batteries overnight.
3. If it still won’t power up, remove the front cover.
4. Check that the cables are plugged into the PC boards.
5. If nothing seems to be amiss, return the unit to AMI for repair.
Analyzer reads too low
1. Sensor is not calibrated. Flow span gas through the analyzer and span the analyzer until it reads
appropriately. Use compressed air or certified calibration gas.
2. Flow rate is inadequate. Increase the flow using the valve on the flowmeter , or else turn on the pump
and adjust the flow.
Analyzer reads too high
1. Verify that the gas flow rate is approximately 1 SCFH.
2. Check for leaks in the sample system using SNOOP or similar.
3. Oxygen diffusion can be a problem. Verify that no silicone tubing is used in the sample system. Use
Copper, Stainless Steel, Teflon, Tygonor similar high quality tubing.
4. Verify the analyzer calibration using air as the span gas.
Analyzer reads zero
1. The analyzer takes about two minutes to warm up. Give it some time!
2. See if it will respond to air. If it does, you have zero oxygen in your sample.
3. If problem persists call AMI for a return authorization number.
Can’t span the unit
1. (The unit won’t respond to the up and down buttons during span)
2. Use the AMI User Interface program to set the security to either “Span only” or “No security”.
3. Once you have spanned it, set the security back again so people do not adjust it in error.