Alicat M-Series User manual

M Series
Precision Gas Mass Flow Meter
Innovative Flow and Pressure Solutions
Operating Manual

03/03/2010 Rev.16 DOC-ALIMAN16
Conformity / Supplemental Information:
The product complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC
(including 93/68/EEC) and carries the CE Marking accordingly. Contact the manufacturer for more information.
Limited Lifetime Warranty
Alicat Scientific, Inc. warrants to the original purchaser (hereinafter referred to as “Buyer”) that instruments manufactured
by Alicat Scientific (hereinafter referred to as “Product”) shall be free from defects in materials and workmanship for the life
of the Products.
Under this warranty, the Product will be repaired or replaced at manufacturer’s option, without charge for parts or labor when
the Product is carried or shipped prepaid to the factory together with proof of purchase.
The foregoing shall constitute the exclusive and sole remedy in lieu of other remedies of the Buyer for any breach by Alicat
Scientific of this warranty to the maximum extent permitted by law.
This warranty does not apply to any Product which has not been installed or used in accordance with the Product operation
and installation specifications provided to Buyer verbally or in writing by Alicat Scientific for the proper and normal use of
the Product.
Buyer agrees hereunder that Alicat reserves the right to void any warranty, written or implied, if upon Alicat’s examination of
Product shall disclose to Alicat’s satisfaction that the Product failure was due solely, or in part, to accident, misuse, neglect,
abuse, alteration, improper installation, unauthorized repair or improper testing by Buyer or agent of Buyer.
Alicat Scientific shall not be liable under any circumstances for indirect, special, consequential, or incidental damages in
connection with, or arising out of, the sale, performance, or use of the Products covered by this warranty.
Alicat Scientific does not recommend, warrant or assume responsibility for the use of the Products in life support applications
or systems.
Alicat’s warranties as herein above set forth shall not be enlarged, diminished or affected by, and no obligation or liability
shall arise or grow out of Alicat’s rendering of technical advice in connection with Buyer’s order of the Products furnished
hereunder.
If Product becomes obsolete, Alicat Scientific, at its own discretion, reserves the right to repair the Product with available
replacement parts or upgrade the Product to a current, commercially available version of the original Product. Should
upgrading the Product be deemed necessary by Alicat, Buyer hereby agrees to pay an upgrade fee equal to seventy percent
of the retail value of the replacement Product. Alicat Scientific hereunder makes no claim that replacement Products will
look, function or operate in the same or similar manner as the original product.
When a Product is returned to Alicat Scientific for recalibration this service is considered normal preventative maintenance.
Recalibration of Product shall not be treated as a warranty service unless recalibration of Product is required as the result
of repairs to Product pursuant to this Warranty. Failure to recalibrate Product on a yearly basis will remove any and
all obligations regarding repair or replacement of Product as outlined by this Warranty to Buyer from Alicat
Scientific.
This Warranty is in lieu of all other relevant warranties, expressed or implied, including the implied warranty of merchantability
and the implied warranty of fitness for a particular purpose, and any warranty against infringement of any patent.
Continued use or possession of Products after expiration of the applicable warranty period stated above shall be conclusive
evidence that the warranty is fulfilled to the full satisfaction of Buyer.
Alicat makes no warranty as to experimental, non-standard or developmental Products.
Accessories purchased from Alicat are not covered by this warranty.
Notice: Alicat Scientific, Inc. reserves the right to make any changes and improvements to the products described in this
manual at any time and without notice. This manual is copyrighted. This document may not, in whole or in part, be copied,
reproduced, translated, or converted to any electronic medium or machine readable form, for commercial purposes,
without prior written consent from the copyright holder.
Note: Although we provide assistance on Alicat Scientific products both personally and through our literature, it is the
complete responsibility of the user to determine the suitability of any product to their application.
Alicat Scientific, Inc.’s Wide-Range Laminar Flow Element Patent: The wide-range laminar flow element and products
using the wide-range laminar flow element are covered by U.S. Patent Number: 5,511,416. Manufacture or use of the
wide-range laminar flow element in products other than Alicat Scientific products or other products licensed under said
patent will be deemed an infringement.

Table of Contents Page
Installation 5
Plumbing 5
Mounting 5
Application 5
Power and Signal Connections 6
RS-232 Digital Output Signal 7
RS-485 Digital Output Signal
Standard Voltage (0-5 Vdc) Output Signal 7
Optional 0-10 Vdc Output Signal 7
Optional Current (4-20 mA) Output Signal 7
Optional 2nd Analog Output Signal 7
M Series Mass Flow Meter Operation 10
Main Mode 10
Tare 10
Gas Absolute Pressure 11
Gas Temperature 11
Volumetric Flow Rate 11
Mass Flow Rate 11
Flashing Error Message 11
Select Menu Mode 12
Gas Select Mode 12
Communication Select Mode 13
Unit ID 13
Baud 13
Data Rate 13
Manufacturer Data Mode 14
Miscellaneous Mode 14
LCD Contrast 15
Display Zero Deadband 15
Pressure Averaging 15
Flow Averaging 15
RS-232 or RS-485 Output and Input 16
Configuring HyperTerminal® 16
Changing from Streaming to Polling Mode 16
Tare 16
Gas Select 17
Collecting Data 18
Data Format 18
Sending a Simple Script File to HyperTerminal® 19

Table of Contents Page
Operating Principle 20
Gas Viscosity 20
Other Gases 21
Volume Flow vs. Mass Flow 21
Volumetric Flow and Mass Flow Conversion 22
Compressibility 22
Standard Gas Data Tables 23
Gas Viscosities, Densities and Compressibilities at 25oC24
Gas Viscosities, Densities and Compressibilities at 0oC25
Troubleshooting 26
Maintenance and Recalibration 27
M Series Technical Specifications 28
M Series Dimensional Drawings 32
PROFIBUS Technical Specifications 35
Additional Information
Option: Totalizing Mode Screen 37
Option: Portable Meters 38
Option: Remote Electronics 39
Accessory: BB-9 Multi-Drop Box 39
Accessory: Flow Vision™ SC 40
Accessories 41
Eight Pin Mini-DIN Pin-Out 42
Locking Industrial Connector Pin-Out 42
PROFIBUS Pin-Out 43
DB15 Pin-Outs 44
Information for CSA and ATEX Labeled Devices 46
Table of Figures
Figure 1. 8 Pin Mini-DIN Connector 6
Figure 2. Mini-DIN to DB-9 Connection for RS-232 Signals 8
Figure 3. Typical Multiple Device (Addressable) Wiring Configuration 8
Figure 4. Optional Industrial Connector 9
Figure 5. Proper Set Up for Remote Tare on Meters 9
Figure 6. Main Mode Display, M Series Flow Meter 10
Figure 7. Select Menu Display 12
Figure 8. Gas Select Mode Display 12
Figure 9. Communication Select Display 13
Figure 10. Manufacturer Data Display 14
Figure 11. Miscellaneous Mode Display 15

5
Thank you for purchasing an M Series Gas Flow Meter. Please take the time to find and read the
information contained in this manual. This will help to ensure that you get the best possible service from
your instrument. This manual covers the following Alicat Scientific instruments:
M Series Mass Gas Flow Meters M-XXSCCM-D
M-XXSLPM-D
This includes M Series devices labeled as approved for CSA Class 1 Div 2 and ATEX Zone 2 hazardous
environments. See pages 46 and 47 for Special Conditions regarding the use of CSA/ATEX labeled
devices.
Alicat Portable Gas Flow Meters
All Alicat Portable Gas Flow Meters operate in accordance with the instructions found in this manual.
Please see page 38 for information regarding battery replacement.
Installation
Plumbing
M Series Gas Flow Meters are equipped with female inlet and outlet port connections (Male VCR fittings
are available as an extra cost option for vacuum applications). Because the flow meters set up a laminar
flow condition within the flow body, no straight runs of pipe are required upstream or downstream of
the meter. The inlet and outlet ports are equal in size and symmetric (in-line). The port sizes (process
connections) and mechanical dimensions for different flow ranges are shown on pages 28-31.
Meters with M5 (10-32) ports have o-ring face seals and require no further sealant or tape. On
other meters, avoid the use of pipe dopes or sealants on the ports as these compounds can cause
permanent damage to the meter should they get into the flow stream. Use of thread sealing Teflon tape
is recommended to prevent leakage around the threads. When applying the tape, avoid wrapping the
first thread or two to minimize the possibility of getting a piece of shredded tape into the flow stream.
When changing fittings, always clean any tape or debris from the port threads.
It is also recommended that a 20 micron filter be installed upstream of meters with full scale ranges of
1 (S)LPM or less and a 50 micron filter be installed upstream of meters with full scale ranges above
1 (S)LPM.
Mounting
M Series Gas Flow Meters have mounting holes for convenient mounting to flat panels. The meters are
position insensitive and can be mounted in any orientation. The sizes and dimensions for the mounting
holes are shown on pages 32-34.
Application
Maximum operating line pressure is 145 PSIG (1 MPa).
Caution: Exceeding the maximum specified line pressure may cause permanent damage to the
solid-state differential pressure transducer.
If the line pressure is higher than 145 PSIG (1 MPa), a pressure regulator should be used upstream
from the flow meter to reduce the pressure to 145 PSIG (1 MPa) or less if possible. Although the meter’s
operation is unidirectional, reversing the flow direction will inflict no damage as long as the maximum
specified limits are not exceeded.
Note: Avoid installations (such as snap acting solenoid valves upstream) that apply instantaneous
high pressure to the meter as permanent damage to the differential pressure sensor could result.
This damage is not covered under warranty!

6
Power and Signal Connections
Power can be supplied to your M Series meter through either the power jack (power jack not available
on CSA/ATEX approved devices) or the 8 pin Mini-DIN connector as shown in Figure 1. An AC to DC
adapter which converts line AC power to DC voltage between 7 and 30 volts is required to use the
power jack (Note: minimum 15Vdc required for 4-20mAoutputs). The adapter current should be at least
100mA. The power jack accepts 2.1 mm female power plugs with positive centers. Cables and AC/DC
adaptors maybe purchased from Alicat (see Accessories page 42) and are commonly available at local
electronics suppliers. Alternatively, power can be supplied through the Mini-DIN connector as shown
below:
7 8
1 2
3 4 5
AC/DC Adapter Jack
6
1
3
2
4 5
678
Pin Function Mini-DIN
cable color
1Inactive or 4-20mA Primary Output Signal Black
2Static 5.12 Vdc or Secondary Analog Output (4-20mA, 5Vdc, 10Vdc) or
Basic Alarm Brown
3 RS-232 Input Signal Red
4 Analog Input Signal = Remote Tare (Ground to Tare) Orange
5 RS-232 Output Signal Yellow
60-5 Vdc (or 0-10 Vdc) Output Signal Green
7 Power In (7-30 Vdc, 100mA) or (15-30Vdc for 4-20mA units) Blue
8 Ground (common for power, communications and signals) Purple
Note: The above pin-out is applicable to all the flow meters and controllers available with the Mini-DIN
connector. The availability of different output signals depends on the flow meter options ordered.
Underlined Items in the above table are optional configurations that are noted on the unit’s calibration
sheet.
Figure 1. 8 Pin Mini-DIN Connector
CAUTION: Do not connect power to pins 1 through 6 as permanent damage can occur!
Note: Upon initial review of the pin out diagram in Figure 1, it is common to mistake Pin 2 (labeled 5.12
Vdc Output) as the standard 0-5 Vdc analog output signal! In fact Pin 2 is normally a constant 5.12 Vdc
that reflects the system bus voltage and can be used as a source for the set-point signal.

7
RS-232 Digital Output Signal
If you will be using the RS-232 output signal, it is necessary to connect the RS-232 Output Signal
(Pin 5), the RS-232 Input Signal (Pin 3), and Ground (Pin 8) to your computer serial port as shown in
Figure 2. Adapter cables are available from the manufacturer or they can be constructed in the field with
parts from an electronics supply house. In Figure 2, note that the diagrams represent the “port” side of
the connections, i.e. the connector on top of the meter and the physical DB-9 serial port on the back of
the computer. The cable ends will be mirror images of the diagram shown in Figure 2. (See page 16 for
details on accessing RS-232 output.)
Optional RS-485 Digital Output Signal
If you will be using the RS-485 output signal, it is necessary to connect the RS-485 Output Signal with
the appropriate DB15 pin out as shown on pages 43 and 44. If your device is configured with a 6-pin
industrial connector please see Figure 4. (See page 16 for details on accessing RS-485 output.)
Standard Voltage (0-5 Vdc) Output Signal
All M Series flow meters have a 0-5 Vdc (optional 0-10 Vdc) output signal available on Pin 6. This is
generally available in addition to other optionally ordered outputs. This voltage is usually in the range of
0.010 Vdc for zero flow and 5.0 Vdc for full-scale flow. The output voltage is linear over the entire range.
Ground for this signal is common on Pin 8.
Optional 0-10 Vdc Output Signal
If your meter was ordered with a 0-10 Vdc output signal, it will be available on Pin 6. (See the Calibration
Data Sheet that shipped with your meter to determine which output signals were ordered.) This voltage
is usually in the range of 0.010 Vdc for zero flow and 10.0 Vdc for full-scale flow. The output voltage is
linear over the entire range. Ground for this signal is common on Pin 8.
Optional Current (4-20 mA) Output Signal
If your meter was ordered with a 4-20 mA current output signal, it will be available on Pin 1. (See the
Calibration Data Sheet that shipped with your meter to determine which output signals were ordered.)
The current signal is 4 mA at 0 flow and 20 mA at the meter’s full scale flow. The output current is
linear over the entire range. Ground for this signal is common on Pin 8. (Current output units require
15-30Vdc power.)
Note: This is a current sourcing device. Do not attempt to connect it to “loop powered’” systems.
Optional 2nd Analog Output Signal
You may specify an optional 2nd analog output on Pin 2 at time of order. (See the Calibration Data
Sheet that shipped with your meter to determine which output signals were ordered.) This output may
be a 0-5 Vdc, 0-10 Vdc, or 4-20 mA analog signal that can represent any measured parameter. With this
optional output, a volumetric flow meter could output the volumetric flow rate with a 0-5 Vdc signal (on
pin 6) and a 4-20 mA signal (on pin 2), or a mass flow meter could output the mass flow rate (0-5 Vdc
on pin 6) and the absolute pressure (0-5 Vdc on pin 2).
If your device is CSA/ATEX approved or equipped with the optional six pin industrial connector, please
contact the factory.
Note: This is a current sourcing device. Do not attempt to connect it to “loop powered” systems.

8
7
4
6
21
DB-9 Serial Port
5
5----------Ground--------------------------------------Ground----------8
3----------Transmit------------------------------------Receive---------3
2----------Receive-------------------------------------Transmit--------5
8 Pin Mini-DIN Port
8
1 2 3 4 5
6 7 8 9
3
45
678
2
Figure 2. Mini-DIN to DB-9 Connection for RS-232 Signals
5
3
2
Purple
Red
Yellow
Purple
Red
Yellow
54321
9876
Unit C
Unit B
Unit A
Female Serial Cable Front
Purple (Ground)
Red
Yellow
Figure 3. Typical Multiple Device (Addressable) Wiring Configuration
Note: The easiest way to connect multiple devices is with a BB-9 Multi-Drop Box (see page 39).
(Note: BB-9 is not compatible with RS-485.)

9
An industrial connector is standard on all CSA/ATEX approved devices (see pages 46 & 47). It is also
available as an option on all other Alicat instruments.
1
6
5
4
3
2
Pin Function Cable Color
1Power In ( + ) Red
2 RS-232TX / RS-485 + Blue
3 RS-232RX / RS-485 - White
4 Remote Tare (Ground to Tare) Green
5 Ground (common for power,
communications and signals)
Black
6 Signal Out (Voltage or Current as ordered) Brown
Figure 4. Optional Industrial Connector
Note: The above pin-out is applicable to all the flow meters and controllers ordered with the industrial
connector. The availability of different output signals depends on the flow meter options ordered.
Figure 5. Proper set up for remote tare on meters (Momentarily ground Pin 4 to Tare)
DB15 Pin-out Diagrams:
Pin-out diagrams for devices ordered with a DB15 connector can be
found on pages 44 and 45 .
PROFIBUS Pin-out Diagrams:
Pin-out diagrams for PROFIBUS configured devices can be found on page 35 and 43.

10
M Series Mass Flow Meter Operation
The M Series Mass Flow Meter provides a multitude of useful flow data in one simple, rugged device.
The M Series can have several screen “modes” depending on how the device is ordered. All M Series
meters have a default Main Mode, Select Menu Mode, a Gas Select Mode (the Gas Select Mode
may not be available on meters calibrated for a custom gas or blend), a Communication Select Mode,
Manufacturer Data Mode and a Miscellaneous Mode. In addition, your device may have been ordered
with the optional Totalizing Mode (page 37). The device defaults to Main Mode as soon as power is
applied to the meter.
Main Mode
The main mode screen defaults on power up with the mass flow on the primary display. The following
parameters are displayed in the main mode as shown in Figure 6:
MODE
PSIA oC Tare
+13.49 +22.73
MASS
SCCM
Air
+0.000 +0.000
Volume Mass Main
Figure 6. Main Mode Display, M Series Flow Meter
The “MODE” button in the lower right hand corner toggles the display between the Main display and the
Select Menu display.
Tare – Pushing the dynamically labeled “Tare” button in the upper right hand corner tares the flow meter
and provides it with a reference point for zero flow. This is a simple but important step in obtaining
accurate measurements. It is good practice to “zero” the flow meter each time it is powered up. If the
flow reading varies significantly from zero after an initial tare, give the unit a minute or so to warm up
and re-zero it.
If possible, zero the unit near the expected operating pressure by positively blocking the flow downstream
of the flow meter prior to pushing the “Tare” button. Zeroing the unit while there is any flow will directly
affect the accuracy by providing a false zero point. If in doubt about whether a zero flow condition exists,
remove the unit from the line and positively block both ports before pressing the “Tare” button. If the unit
reads a significant negative value when removed from the line and blocked, it is a good indication that
it was given a false zero. It is better to zero the unit at atmospheric pressure and a confirmed no flow
conditions than to give it a false zero under line pressure.
Note: A remote tare can be achieved by momentarily grounding pin 4 to tare as shown in Figure 5 on
page 9.

11
Gas Absolute Pressure: The M Series flow meters utilize an absolute pressure sensor to measure
the line pressure of the gas flow being monitored. This sensor references hard vacuum and accurately
reads line pressure both above and below local atmospheric pressure. This parameter is located in
the upper left corner of the display under the dynamic label “PSIA”. This parameter can be moved to
the primary display by pushing the button just above the dynamic label (top left). The engineering unit
associated with absolute pressure is pounds per square inch absolute (PSIA). This can be converted
to gage pressure (psig = the reading obtained by a pressure gauge that reads zero at atmospheric
pressure) by simply subtracting local atmospheric pressure from the absolute pressure reading:
PSIG = PSIA – (Local Atmospheric Pressure)
The flow meters use the absolute pressure of the gas in the calculation of the mass flow rate. For
working in metric units, note that 1 PSI = 6.89 kPa.
Gas Temperature: The M Series flow meters also utilize a temperature sensor to measure the line
temperature of the gas flow being monitored. The temperature is displayed in engineering units of
degrees Celsius (°C). The flow meters use the temperature of the gas in the calculation of the mass
flow rate. This parameter is located in the upper middle portion of the display under “°C”. This parameter
can be moved to the primary display by pushing the top center button above “°C”.
Volumetric Flow Rate: The volumetric flow rate is determined using the Flow Measurement Operating
Principle described elsewhere in this manual. This parameter is located in the lower left corner of the
display over “Volume”. This parameter can be moved to the primary display by pushing the “Volume”
button (lower left). In order to get an accurate volumetric flow rate, the gas being measured must be
selected (see Gas Select Mode). This is important because the device calculates the flow rate based on
the viscosity of the gas at the measured temperature. If the gas being measured is not what is selected,
an incorrect value for the viscosity of the gas will be used in the calculation of flow, and the resulting
output will be inaccurate in direct proportion to the ratio between the two gases viscosities.
Mass Flow Rate: The mass flow rate is the volumetric flow rate corrected to a standard temperature
and pressure (typically 14.696 psia and 25°C). This parameter is located in the lower middle portion
of the display over “Mass”. This parameter can be moved to the primary display by pushing the button
located below “Mass” (bottom center). The meter uses the measured temperature and the measured
absolute pressure to calculate what the flow rate would be if the gas pressure was at 1 atmosphere and
the gas temperature was 25°C. This allows a solid reference point for comparing one flow to another.
Flashing Error Message: Our flow meters and controllers display an error message (MOV = mass
overrange, VOV = volumetric overrange, POV = pressure overrange, TOV = temperature overrange)
when a measured parameter exceeds the range of the sensors in the device. When any item flashes
on the display, neither the flashing parameter nor the mass flow measurement is accurate. Reducing
the value of the flashing parameter to within specified limits will return the unit to normal operation and
accuracy.

12
Select Menu Mode
Pushing “Mode” once will bring up the “Select Menu” display. Push the button nearest your selection to
go to the corresponding screen. Push “Mode” again to return to the Main Mode display. (Note: If your
meter was ordered with Totalizing Mode option (page 37), pushing the “Mode” button once will bring up
the “Totalizing Mode” display. Pushing “Mode” a second time will bring up the “Select Menu” display.)
MODE
Gas Misc
SELECT
MENU
Comm. Mfg.
RS232 Data Menu
Figure 7. Select Menu Display
Gas Select Mode
The gas select mode is accessed by pressing the button above “Gas” on the Select Menu display. The
screen will appear as shown in Figure 8 below.
PgUP PgDWN Main
H2 Hydrogen
He Helium
>N2 Nitrogen
N2O Nitrous Oxide
Ne Neon
O2 Oxygen
UP DOWN Gas
MODE
Figure 8. Gas Select Display
The selected gas is displayed on the default main mode screen as shown in Figure 6, and is indicated
by the arrow in the Gas Select Mode screen in Figure 8. To change the selected gas, use the buttons
under “UP” and “DOWN” or above “PgUP” and “PgDWN” to position the arrow in front of the desired
gas. When the mode is cycled back to the Main Mode, the selected gas will be displayed on the main
screen. (Note: Gas Select Mode may not be available for units ordered for use with a custom gas or
blend.)

13
Communication Select
The Communication Select mode is accessed by pressing the button below “Comm. RS-232” or “Comm.
RS-485” on the Select Menu display. The screen will appear as shown in Figure 9 below.
Select
>
Unit ID (A).....A
Baud (19200)....19200
Data Rate......Fast
Comm.
UP DOWN RS-232
MODE
Figure 9. Communication Select Display
Unit ID – Valid unit identifiers are letters A-Z and @ (see Note below). This identifier allows the user to
assign a unique address to each device so that multiple units can be connected to a single RS-232 or
RS-485 port on a computer. The Communication Select Mode allows you to view and/or change a unit’s
unique address. To change the unit ID address, press the “Select” button in the upper left corner of the
display until the cursor arrow is in front of the word “Unit ID”. Then, using the UP and DOWN buttons at
the bottom of the display, change the unit ID to the desired letter. Any ID change will take effect when
the Communication Select Screen is exited by pushing the MODE or Main button.
Note: When the symbol @ is selected as the unit ID, the device will go into streaming mode when
the Communication Select Mode is exited by pushing the MODE or Main button. See the RS-232
Communications chapter in this manual for information about the streaming mode. Note: RS-485 units
do not have a streaming mode.
Baud – The baud rate (bits per second) determines the rate at which data is passed back and forth
between the instrument and the computer. Both devices must send/receive at the same baud rate in
order for the devices to communicate via RS-232 or RS-485. The default baud rate for these devices
is 19200 baud, sometimes referred to as 19.2K baud. To change the baud rate in the Communication
Select Mode, press the “Select” button in the upper left corner of the display until the cursor arrow is
in front of the word “Baud”. Then, using the UP and DOWN buttons at the bottom of the display, select
the required baud rate to match your computer or PLC. The choices are 38400, 19200, 9600, or 2400
baud. Any baud rate change will not take effect until power to the unit is cycled.
Data Rate – Changing the Data Rate affects the rate at which the instrument dumps its data. Slow is
½ the Fast rate. The speed of the Fast rate is determined by the selected baud rate. It is sometimes
desirable to reduce the data rate if the communication speed bogs down the computer’s processor (as
is not uncommon in older laptops), or to reduce the size of data files collected in the streaming mode.
To change the data rate in the Communication Select Mode, press the “Select” button in the upper left
corner of the display until the cursor arrow is in front of the word “Data Rate”. Then, using the UP and
DOWN buttons at the bottom of the display, select either Fast or Slow. Any data rate change will be
effective immediately upon changing the value between Fast and Slow.

14
Manufacturer Data
“Manufacturer Data” is accessed by pressing the “Mfg. Data” button on the Select Menu display
(Figure 7). The “Mfg 1” display shows the name and telephone number of the manufacturer. The “Mfg 2”
display shows important information about your flow meter including the model number, serial number,
and date of manufacture.
MODE
Main
Alicat Scientific, Inc.
Ph 520-290-6060
Fax [phone]
Mfg 1
MODE
Main
Model MC-10SLPM-D
Serial No 47117
Date Mfg.11/07/2009
Calibrated By.DL
Software GP07R23
Mfg 2
Figure 10. Manufacturer Data Displays
Miscellaneous Mode
The Miscellaneous mode is accessed by pressing the button above the “Misc” label in the upper right
hand corner of the Select Menu display. The screen will appear as shown in Figure 11. Push the button
above “Select” to move the cursor even with the item you wish to adjust. Then use the “UP” and “DOWN”
buttons to make the adjustment.
NOTE: All Miscellaneous changes are recorded when you exit the Miscellaneous display.

15
MODE
Select Main
>
LCD Contrast(10). 10
PVM DBand (0.5
%
FS)0.5
PRESS Avg (008) . . . 008
FLOW Avg (100) . . . . 100
UP DOWN Misc
Figure 11. Miscellaneous Display
LCD Contrast: The Liquid Crystal Display Contrast can be adjusted between 0 and 30 with zero being
the lightest contrast and 30 being the darkest contrast. To change the contrast, press the “Select”
button in the upper left hand corner of the display until the cursor arrow is in front of the words “LCD
Contrast (X)”. Then using the UP and DOWN buttons at the bottom of the display, change the contrast
value as desired. The change is immediate and the effect can be monitored as the value is changed.
Display Zero Deadband: Zero deadband refers to a value below which the display simply jumps to
zero. This deadband is often desired to prevent electrical noise from showing up on the display as minor
flows or pressures that do not actually exist, especially in high noise (electrical) environments. This
display deadband does not affect the analog or digital signal outputs — there is no zero deadband on the
output signals. The display zero deadband can be adjusted between 0 and 3.2% of the Full Scale (FS)
of the sensor. PVM refers to Pressure, Volumetric Flow and Mass Flow, the three parameters to which
the deadband applies. To adjust the display zero deadband, press the “Select” button in the upper left
hand corner of the display until the cursor arrow is in front of the words “PVM DBand (X %F.S.)”. Then
using the UP and DOWN buttons at the bottom of the display, change the display zero deadband value
as desired.
Pressure Averaging: It is sometimes advantageous to apply an averaging factor to the pressure output
(and display) to make it easier to read and interpret rapidly fluctuating pressures. Pressure averaging
can be adjusted between 1 (no averaging) and 256 (maximum averaging). This is a geometric running
average where the number between 1 and 256 can be considered very roughly equivalent to the
response time constant in milliseconds. This can be very effective at “smoothing” high frequency process
oscillations such as those caused by diaphragm pumps. To adjust the pressure averaging, press the
“Select” button in the upper left hand corner of the display until the cursor arrow is in front of the words
“PRESS Avg (XXX)”. Then using the UP and DOWN buttons at the bottom of the display, change the
pressure averaging value as desired.
Flow Averaging: It is sometimes advantageous to apply an averaging factor to the flow output (and
display) to make it easier to read and interpret rapidly fluctuating flows. Flow averaging can be adjusted
between 1 (no averaging) and 256 (maximum averaging). This is a geometric running average where
the number between 1 and 256 can be considered very roughly equivalent to the response time constant
in milliseconds. This can be very effective at “smoothing” high frequency process oscillations such as
those caused by diaphragm pumps. To adjust the flow averaging, press the “Select” button in the upper
left hand corner of the display until the cursor arrow is in front of the words “FLOW Avg (XXX)”. Then
using the UP and DOWN buttons at the bottom of the display, change the flow averaging value as
desired.

16
RS-232 / RS-485 Output and Input
Configuring HyperTerminal®:
Open your HyperTerminal® RS-232 / RS-485 terminal program (installed under the “Accessories”1.
menu on all Microsoft Windows® operating systems).
Select “Properties” from the file menu.2.
Click on the “Configure” button under the “Connect To” tab. Be sure the program is set for: 19,2003.
baud (or matches the baud rate selected in the RS-232 / RS-485 communications menu on the
meter) and an 8-N-1-None (8 Data Bits, No Parity, 1 Stop Bit, and no Flow Control) protocol.
Under the “Settings” tab, make sure the Terminal Emulation is set to ANSI or Auto Detect.4.
Click on the “ASCII Setup” button and be sure the “Send Line Ends with Line Feeds” box5. is not
checked and the “Echo Typed Characters Locally” box and the “Append Line Feeds to Incoming
Lines” boxes are checked. Those settings not mentioned here are normally okay in the default
position.
Save the settings, close HyperTerminal® and reopen it.6.
In Polling Mode, the screen should be blank except the blinking cursor. In order to get the data streaming to
the screen, hit the “Enter” key several times to clear any extraneous information. Type “*@=@” followed
by “Enter” (or using the RS-232 / RS-485 communication select menu, select @ as identifier and exit
the screen). If data still does not appear, check all the connections and com port assignments.
Changing From Streaming to Polling Mode:
When the meter is in the Streaming Mode (RS-485 units do not have a streaming mode), the screen is
updated approximately 10-60 times per second (depending on the amount of data on each line) so that
the user sees the data essentially in real time. It is sometimes desirable, and necessary when using
more than one unit on a single RS-232 line, to be able to poll the unit.
In Polling Mode the unit measures the flow normally, but only sends a line of data when it is “polled”.
Each unit can be given its own unique identifier or address. Unless otherwise specified each unit is
shipped with a default address of capital A. Other valid addresses are B thru Z.
Once you have established communication with the unit and have a stream of information filling your
screen:
Type *@=A followed by “Enter” (or using the RS-232 / RS-485 communication select menu, select1.
A as identifier and exit the screen) to stop the streaming mode of information. Note that the flow of
information will not stop while you are typing and you will not be able to read what you have typed.
Also, the unit does not accept a backspace or delete in the line so it must be typed correctly. If in
doubt, simply hit enter and start again. If the unit does not get exactly what it is expecting, it will
ignore it. If the line has been typed correctly, the data will stop.
You may now poll the unit by typing A followed by “Enter”. This does an instantaneous poll of unit2.
A and returns the values once. You may type A “Enter” as many times as you like. Alternately you
could resume streaming mode by typing *@=@ followed by “Enter”. Repeat step 1 to remove the
unit from the streaming mode.
To assign the unit a new address, type *@=New Address, e.g. *@=B. Care should be taken not3.
to assign an address to a unit if more than one unit is on the RS-232 / RS-485 line as all of the
addresses will be reassigned. Instead, each should be individually attached to the RS-232 / RS-485
line, given an address, and taken off. After each unit has been given a unique address, they can all
be put back on the same line and polled individually.
Tare –Tareing (or zeroing) the flow meter provides it with a reference point for zero flow. This is a simple
but important step in obtaining accurate measurements. It is good practice to “zero” the flow meter each
time it is powered up. A unit may be Tared by following the instructions on page 10 or it may be Tared
via RS-232 / RS-485 input.

17
To send a Tare command via RS-232 / RS-485, enter the following strings:
In Streaming Mode: $$V<Enter>
In Polling Mode: Address$$V<Enter> (e.g. B$$V<Enter>)
Gas Select – The selected gas can be changed via RS-232 / RS-485 input. To change the selected
gas, enter the following commands:
In Streaming Mode: $$#<Enter>
In Polling Mode: Address$$#<Enter> (e.g. B$$#<Enter>)
Where # is the number of the gas selected from the table below. Note that this also corresponds to the
gas select menu on the flow meter screen:
# GAS
0 Air Air
1 Argon Ar
2 Methane CH4
3 Carbon Monoxide CO
4 Carbon Dioxide CO2
5 Ethane C2H6
6 Hydrogen H2
7 Helium He
8 Nitrogen N2
9 Nitrous Oxide N2O
10 Neon Ne
11 Oxygen O2
12 Propane C3H8
13 normal-Butane n-C4H10
14 Acetylene C2H2
15 Ethylene C2H4
16 iso-Butane i-C2H10
17 Krypton Kr
18 Xenon Xe
19 Sulfur Hexafluoride SF6
20 75% Argon / 25% CO2 C-25
21 90% Argon / 10% CO2 C-10
22 92% Argon / 8% CO2 C-8
23 98% Argon / 2% CO2 C-2
24 75% CO2 / 25% Argon C-75
25 75% Argon / 25% Helium A-75
26 75% Helium / 25% Argon A-25
27 90% Helium / 7.5% Argon / 2.5% CO2
(Praxair - Helistar® A1025)
A1025
28 90% Argon / 8% CO2 / 2% Oxygen
(Praxair - Stargon® CS)
Star29
29 95% Argon / 5% Methane P-5
For example, to select Propane, enter: $$12<Enter>

18
Collecting Data:
The RS-232 / RS-485 output updates to the screen many times per second. Very short-term events
can be captured simply by disconnecting (there are two telephone symbol icons at the top of the
HyperTerminal® screen for disconnecting and connecting) immediately after the event in question. The
scroll bar can be driven up to the event and all of the data associated with the event can be selected,
copied, and pasted into Microsoft® Excel® or other spreadsheet program as described below.
For longer term data, it is useful to capture the data in a text file. With the desired data streaming to the
screen, select “Capture Text” from the Transfer Menu. Type in the path and file name you wish to use.
Push the start button. When the data collection period is complete, simply select “Capture Text” from
the Transfer Menu and select “Stop” from the sub-menu that appears.
Data that is selected and copied, either directly from HyperTerminal® or from a text file can be pasted
directly into Excel®. When the data is pasted it will all be in the selected column. Select “Text to
Columns...” under the Data menu in Excel® and a Text to Columns Wizard (dialog box) will appear.
Make sure that “Fixed Width” is selected under Original Data Type in the first dialog box and click “Next”.
In the second dialog box, set the column widths as desired, but the default is usually acceptable. Click
on “Next” again. In the third dialog box, make sure the column data format is set to “General”, and click
“Finish”. This separates the data into columns for manipulation and removes symbols such as the plus
signs from the numbers. Once the data is in this format, it can be graphed or manipulated as desired.
For extended term data capture see: “Sending a Simple Script to HyperTerminal®” on page 19.
Data Format:
The data stream on the screen represents the flow parameters of the main mode in the units shown on
the display.
For mass flow meters, there are five columns of data representing pressure, temperature, volumetric
flow, mass flow and the selected gas. The first column is absolute pressure (normally in PSIA), the
second column is temperature (normally in °C), the third column is volumetric flow rate (in the units
specified at time of order and shown on the display), and the fourth column is mass flow (also in the
units specified at time of order and shown on the display). For instance, if the meter was ordered in
units of SCFM, the display on the meter would read 2.004 SCFM and the last two columns of the output
below would represent volumetric flow and mass flow in CFM and SCFM respectively.
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
M Series Mass Flow Meter Data Format
Note: On units with the totalizer function the fifth column will be the totalizer value, with gas select
moving to a sixth column.

19
Sending a Simple Script File to HyperTerminal®
It is sometimes desirable to capture data for an extended period of time. Standard streaming mode
information is useful for short term events, however, when capturing data for an extended period of
time, the amount of data and thus the file size can become too large very quickly. Without any special
programming skills, the user can use HyperTerminal and a text editing program such as Microsoft Word
to capture text at user defined intervals.
1. Open your text editing program, MS Word for example.
2. Set the cap lock on so that you are typing in capital letters.
3. Beginning at the top of the page, typeA<Enter> repeatedly. If you’re using MS Word, you can tell how
many lines you have by the line count at the bottom of the screen. The number of lines will correspond
to the total number of times the flow device will be polled, and thus the total number of lines of data it
will produce.
For example: A
A
A
A
A
A
will get a total of six lines of data from the flow meter, but you can enter as many as you like.
The time between each line will be set in HyperTerminal.
4. When you have as many lines as you wish, go to the File menu and select save. In the save dialog
box, enter a path and file name as desired and in the “Save as Type” box, select the plain text (.txt)
option. It is important that it be saved as a generic text file for HyperTerminal to work with it.
5. Click Save.
6. A file conversion box will appear. In the “End Lines With” drop down box, select CR Only. Everything
else can be left as default.
7. Click O.K.
8. You have now created a “script” file to send to HyperTerminal. Close the file and exit the text editing
program.
9. Open HyperTerminal and establish communication with your flow device as outlined in the manual.
10. Set the flow device to Polling Mode as described in the manual. Each time you type A<Enter>, the
meter should return one line of data to the screen.
11. Go to the File menu in HyperTerminal and select “Properties”.
12. Select the “Settings” tab.
13. Click on the “ASCII Setup” button.
14. The “Line Delay” box is defaulted to 0 milliseconds.This is where you will tell the program how often
to read a line from the script file you’ve created. 1000 milliseconds is one second, so if you want a line
of data every 30 seconds, you would enter 30000 into the box. If you want a line every 5 minutes, you
would enter 300000 into the box.
15. When you have entered the value you want, click on OK and OK in the Properties dialog box.
16. Go the Transfer menu and select “Send Text File…” (NOT Send File…).
17. Browse and select the text “script” file you created.
18. Click Open.
19. The program will begin “executing” your script file, reading one line at a time with the line delay you
specified and the flow device will respond by sending one line of data for each poll it receives, when it
receives it.
You can also capture the data to another file as described in the manual under “Collecting Data”. You
will be simultaneously sending it a script file and capturing the output to a separate file for analysis.

20
Operating Principle
M Series Gas Flow Meters are based on the accurate measurement of volumetric flow. The volumetric
flow rate is determined by creating a pressure drop across a unique internal restriction, known as a
Laminar Flow Element (LFE), and measuring differential pressure across it. The restriction is designed
so that the gas molecules are forced to move in parallel paths along the entire length of the passage;
hence laminar (streamline) flow is established for the entire range of operation of the device. Unlike
other flow measuring devices, in laminar flow meters the relationship between pressure drop and flow
is linear. The underlying principle of operation of the 16 Series flow meters is known as the Poiseuille
Equation:
Q = (P1-P2)r4/8ηL (Equation 1)
Where: Q = Volumetric Flow Rate
P
1= Static pressure at the inlet
P
2= Static pressure at the outlet
r = Radius of the restriction
η= (eta) absolute viscosity of the fluid
L = Length of the restriction
Since , r and L are constant; Equation 1 can be rewritten as:
Q = K (∆P/η) (Equation 2)
Where K is a constant factor determined by the geometry of the restriction. Equation 2 shows the linear
relationship between volumetric flow rate (Q) differential pressure (∆P) and absolute viscosity (η) in a
simpler form.
Gas Viscosity: In order to get an accurate volumetric flow rate, the gas being measured must be
selected (see Gas Select Mode, page 12). This is important because the device calculates the flow rate
based on the viscosity of the gas at the measured temperature. If the gas being measured is not what
is selected, an incorrect value for the viscosity of the gas will be used in the calculation of flow, and the
resulting output will be inaccurate in direct proportion to the difference in the two gases viscosities.
Gas viscosity, and thus gas composition, can be very important to the accuracy of the meter. Anything
that has an effect on the gas viscosity (e.g. water vapor, odorant additives, etc.) will have a direct
proportional effect on the accuracy. Selecting methane and measuring natural gas for instance, will
result in a fairly decent reading, but it is not highly accurate (errors are typically < 0.6%) because
natural gas contains small and varying amounts of other gases such as butane and propane that result
in a viscosity that is somewhat different than pure methane.
Absolute viscosity changes very little with pressure (within the operating ranges of these meters) therefore
a true volumetric reading does not require a correction for pressure. Changes in gas temperature do
affect viscosity. For this reason, the M Series internally compensate for this change.