Matheson 819 Series User manual

INT-0323-rev B
Page 1
Precision Mass Flow Meter
Model 819 Series
Operating Manual
READ AND COMPLY WITH THESE INSTRUCTIONS
BEFORE INSTALLING, OPERATING, OR SERVICING

2
Notice: The manufacturer 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 our 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.
The manufacturer does not warrant or assume responsibility for the use of its
products in life support applications or systems.
W arranty
This product is warranted to the original purchaser for a period of one year
from the date of purchase to be free of defects in material or workmanship.
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. This warranty does not
apply to cosmetic items, nor to products that are damaged, defaced or otherwise
misused or subjected to abnormal use. See “Application” under the Installation
section. Where consistent with state law, the manufacturer shall not be liable for
consequential economic, property, or personal injury damages. The manufacturer
does not warrant or assume responsibility for the use of its products in life support
applications or systems.
Conformity / Supplemental Information:
The product complies with the requirements of the Low Voltage Directive 2006/95/
EC and the EMC Directive 2004/108/EC and carries the CE Marking accordingly.
Contact the manufacturer for more information.

3
Thank you for purchasing a MATHESON Gas Flow Meter.
Please take the time to 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 MATHESON instruments:
819-Series Mass Gas Flow Meters
Unless otherwise noted, the instructions in this manual are applicable to all of
the above instruments.
Full specifications for each device can be found on pages 53 through 68.
Please contact MATHESON at 1-800-828-4313 if you have any
questions regarding the use or operation of this device.

4
TABLE OF CONTENTS
Page
GETTING STARTED
6
MOUNTING
6
PLUMBING
6
POWER AND SIGNAL CONNECTIONS
8
INPUT SIGNALS
8
Analog Input Signal
8
RS-232 Digital Input Signal
9
OUTPUT SIGNALS
9
RS-232 Digital Output Signal
9
Standard Voltage (0-5 Vdc) Output Signal
9
Optional Current (4-20 mA) Output Signal
9
DISPLAYS AND MENUS
10
MAIN
11
Gas Absolute Pressure
11
Gas Temperature
11
Tare
11
Volumetric Flow Rate
12
Mass Flow Rate
12
Flashing Error Message
12
SELECT MENU
13
GAS SELECT
14
Composer
15
COMMUNICATION SELECT
17
Unit ID
17
Baud
17
MISCELLANEOUS
18
MISC1
18
Zero Band
18
Pressure Averaging
18
Flow Averaging
18
LCD Contrast
18
MISC2
19
STP/NTP
19
DIAG TEST
20
Rotate Display
20
DEVICE UNITS
20
MANUFACTURER DATA
21

5
TABLE OF CONTENTS
Page
RS-232 Output and Input
22
Configuring HyperTerminal®
22
Streaming Mode
22
Tareing via RS-232
23
Changing from Streaming to Polling Mode
23
Gas Select
24
Creating and Deleting Gas Mixtures using RS-232
25
Collecting Data
26
Data Format
26
Sending a Simple Script File to HyperTerminal®
27
Operating Principle
28
Standard Gas Data Tables
28
Gas Lists with Viscosities, Densities and Compressibilities
29
Supported Units List
35
Troubleshooting
37
Maintenance and Recalibration
39
Option: Totalizing Mode
40
819-Series Technical Specifications
41
RJ45 Pin-Out Diagram
45

6
GETTING STARTED
Power Jack 8 Pin Mini-DIN
Display Screen
Inlet Connection Port
Outlet Connection Port
Flow Direction Arrow
MOUNTING
Medium Mass Flow Meter
819-Series Gas Flow Meters have holes on the bottom for mounting to flat
panels. See pages 41-44.
819-Series Meters can usually be mounted in any position. No straight runs of
pipe are required upstream or downstream of the meter.
PLUMBING
Your meter is shipped with plastic plugs fitted in the port openings. To
lessen the chance of contaminating the flow stream do not remove
these plugs until you are ready to install the device.
Make sure that the gas will flow in the direction indicated by the flow arrow.
Standard 819-Series Gas Flow Meters have female inlet and outlet port
connections. Welded VCR and other specialty fittings may have male ports.
The inlet and outlet port sizes (process connections) for different flow ranges
are shown on pages 41-44.
Do not use thread sealing Teflon® tape on compression fittings.
On NPT threaded connections, do not wrap the first two threads. This will
minimize the possibility of getting tape into the flow stream and flow body.
Do not use pipe dopes or sealants on the process connections as these
compounds can cause permanent damage to the meter should they get
into the flow stream.

7
We recommend the use of in-line sintered filters to prevent large particulates
from entering the measurement head of the instrument. Suggested maximum
particulate sizes are as follows:
15 microns for units with FS flow ranges between 0-100 sccm and 0-1 slpm.
50 microns for units with FS flow ranges of 0-1 slpm or more.
PRESSURE
Maximum operating line pressure for 819-Series units is 150 psig (1 MPa).
If the line pressure is higher than 150 psig (1 MPa), use a pressure regulator
upstream from the flow meter to reduce the pressure to 150 psig (1 MPa) or less.
Exceeding the maximum specified line pressure may cause permanent
damage to the solid-state differential pressure sensor.
Do Not subject an 819-Series Differential Pressure sensor t o
upstream-downstream pressure differentials exceeding 75PSID.
While high static pressure will typically not damage the dp
sensor, sudden pressure “spikes” can result in complete failure
of the sensor.
A common cause of this problem is instantaneous application of high-
pressure gas as from a snap acting solenoid valve either upstream or
downstream of the meter. If you suspect that your pressure sensor is
damaged please discontinue use of the meter and contact MATHESON.

8
POWER AND SIGNAL CONNECTIONS
Power can be supplied to your controller through either the power jack or the RJ45
connector.
An AC to DC adapter which converts line AC power to DC voltage and current as
specified below is required to use the power jack.
819 meters require a 7-30 Vdc power supply with a 2.1 mm female positive
center plug capable of supplying at least 100mA.
Note: 4-20mA analog output requires at least 15 Vdc.
1 2 3 4 5 6 7 8
RJ45 Device
8 7 6 5 4 3 2 1
RJ45 Cable
1. RS-232 Receive
2. Ground
3. Analog Output
4. RS-232 T ransmit
5. Power Supply
6. Power Supply
7. Analog Input
8. Ground
INPUT SIGNALS
Analog Input Signal
Apply analog input to Pin 7.
Standard 0-5 Vdc is the standard analog input signal. Apply the 0-5 Vdc input
signal to pin 7, with common ground on pin 8.
Optional 4-20 mA: If specified at time of order, a 4-20 mA input signal can be
applied to pin 7, with common ground on pin 8.
NOTE: This is a current sinking device. The receiving circuit is essentially
a 250 ohm resistor to ground.
CAUTION! Do not connect this device to “loop powered’” systems, as
this will destroy portions of the circuitry and void the warranty. If you
must interface with existing loop powered systems, always use a
signal isolator and a separate power supply.

9
RS-232 Digital Input Signal
To use the RS-232 input signal, 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 below. (See page 22 for details on accessing RS-232)
5 4 3 2 1 1 2 3 4 5
9 8 7 6
6 7 8 9
Serial Cable End PC Serial Port
OUTPUT SIGNALS
RS-232 Digital Output Signal
To use the RS-232 output signal, it is necessary to connect the RS-232 Output Signal
(Pin 4), the RS-232 Input Signal (Pin 1), and Ground (Pin 8) to your computer serial
port as shown. (See page 22 for details on accessing RS-232 output.)
Standard Voltage (0-5 Vdc) Output Signal
829-Series flow controllers equipped with a 0-5 Vdc (optional 0-10 Vdc) will have
this output signal available on Pin 3. This output 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 Current (4-20 mA) Output Signal
If your controller was ordered with a 4-20 mA current output signal, it will
be available on Pin 3. (See the Calibration Data Sheet that shipped with your
controller to determine which output signals were ordered.) The current signal
is 4 mA at 0 flow and 20 mA at the controller’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.)

10
S CC M
00123.45
DISPLAYS AND MENUS
The device screen defaults to Main display as soon as power is applied to the meter.
PS I A
+13 . 60
Main
# C
+2 1. 50
TAR E V
The Main display shows pressure,
temperature, volumetric flow and mass
flow.
Pressing the button adjacent to a
+0.00
A ir
parameter will make that parameter
the primary display unit.
By hitting the MENU button at the
+ 0 . 000
CC M
+ 0 . 000
S CC MM
E NU /
T O T A L bottom right of the screen you will
enter the Select Menu display.
Totalizer (option only) If your meter was ordered with the
Totalizer option (page 40), pushing the
TOTAL button once will bring up the
T OT A L /
T I M E R
P E AK
+0 . 0
S CC M
+0 . 0
S c m 3
Totalizing Mode display. Pushing MENU
will bring up the Select Menu display.
2 : 05 h : m : s
M E NU /
BACK R E S E T M A IN
Select Menu Select Menu
From Select Menu you can change
M IS C
GA S
S ELE C T
M F G
DATA
R S 232
C O MM
M A IN
the selected gas, interact with
your RS-232 settings or read
manufacturer ’s data.
Push MAIN to return to the Main display.

11
S CC M
A ir
MAIN
PS I A
+13 . 60
# C
+2 1. 50
TARE V
This mode defaults on power up, with
mass flow as the primary displayed
parameter.
The following parameters are displayed in
the Main mode.
+0.00
S CC M
Gas Absolute Pressure: This sensor
+ 0 . 000
CC M
M a ss F lo w
+ 0 . 000
S CC M
A ir
M E NU /
TOT A L
references hard vacuum and reads
incoming pressure both above and below
local atmospheric pressure. This parameter
is moved to the primary display by pushing
the button above PSIA.
The engineering unit associated with
absolute pressure is pounds per square
inch absolute (psia). This can be converted
to gage pressure (psig) by subtracting local atmospheric pressure from the
absolute pressure reading:
PSIG = PSIA – (Local Atmospheric Pressure)
Gas Temperature: 819-Series flow meters
measure the incoming temperature of the
gas flow. The temperature is displayed
U P
># C
K
# F
# R
DO W N M O D E in degrees Celsius (°C). This parameter is
moved to the primary display by pushing
the button above °C.
Pushing the button again allows you to
select 0 C (Celsius), K (Kelvin), 0 F (Fahrenheit)
or 0 R (Rankine) for the temperature scale.
CANCEL S E T To select a temperature scale, use the UP
and DOWN buttons to position the arrow in
front of the desired scale.
Press SET to record your selection and
return to the MAIN display. The selected
temperature scale will be displayed on the screen.
Tare: Pushing the TARE V button tares the flow meter and provides it with a
reference point for zero flow. This is an important step in obtaining accurate
measurements. It is best 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

12
before pressing the TARE button. If the unit reads a significant negative value
when removed from the line and blocked, it was given a false zero. It is better
to zero the unit at atmospheric pressure and a confirmed no flow condition
than to give it a false zero under line pressure.
Volumetric Flow Rate: This parameter is located in the lower left of the display.
It is moved to the primary display by pushing the button below CCM in this
example. Your display may show a different unit of measure.
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 of the display. It can be moved to
the primary display by pushing the button below SCCM in this example. Your
display may show a different unit of measure preceded by the letter S.
To get an accurate volumetric or mass flow rate, the gas being measured
must be selected. See Gas Select, page 14.
MENU: Pressing MENU switches the screen to the Select Menu display.
Flashing Error Message: An error message (MOV = mass overrange,
VOV = volumetric overrange, POV = pressure overrange, TOV =
temperature overrange) flashes when a measured parameter exceeds
the range of the sensor. When any item flashes, 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.
If the unit does not return to normal operation contact MATHESON.

13
SELECT MENU
From Select Menu you can change the selected gas, interact with your RS-232
settings or read manufacturer’s data.
Press the button next to the desired operation to bring that function to the screen.
M a t h e s o n
M OD EL
IN F O
M IS C 1
M IS C 2 Ph
800 -8 28 -4 3 13
UNIT ID
A
B AUD
19 200
BACK M A IN
B A C K
D E V IC E
UNITS
M A IN
Manufacturer Data
BACK M A IN
Miscellaneous Communications Select
U P
>R ece n t
S t a nd a r d
DO W N P A G E
M I S C M F G
DATA
R S 232
C O MM
PSI A
+13 . 60
# C
+2 1. 50
TA RE V
F ac t o r y C u s t o m
C O M P O S E R U s e r M ix e s
B io r eac t o r
B r ea t hing
GA S
S ELE C T
M AIN
+ 0.00
S CC M
A ir
C h r o m a t og r a phy
F u e l
CANCEL S ELE C T
+ 0 . 000
CC M
+ 0 . 000
S CC M
M A IN
Gas Select
Select Menu
Main
An explanation for each screen can be found on the following pages.

14
GAS SELECT™
U P
>R ece n t
S t a nd a r d
DO W N P A G E
Gas Select allows you to set your
device to up to 150 standard gases and
mixes. You can also use COMPOSER to
program and store up to 20 additional
gas mixes.
F ac t o r y C u s t o m
C O M P O S E R U s e r M ix e s
B io r eac t o r
B r ea t h in g
C h r o m a t og r a phy
F u e l
CANCEL S E T
Gas Select is accessed by pressing the
button below GAS SELECT on the Select
Menu display.
To select a gas, use the UP and DOWN
buttons to position the arrow in front of
the desired gas category.
U P
> F u e l
L a s e r
DO W N P A G E
O2 C on ce n t r a t o r
P u r e N on -C o rr o s iv e
S t ac k
W e ldin g
CANCEL S E T
» Recent: Eight most recent selections
» Standard: Gases and mixes standard
MATHESON instruments (page 29)
» Factory Custom: Present only if customer
requested gases were added at the factory
» COMPOSER User Mixes: Gas mixes
programmed by the user (page 15)
» Bioreactor (page 31)
» Breathing (page 32)
» Chromatography (page 34)
» Fuel (page 33)
» Laser (page 33)
» O2 Concentrator (page 34)
» Pure Non-Corrosive (page 29)
» Stack (page 34)
» Welding (page 30)
Press PAGE to view a new page in the
gas category list.
Press SELECT to view the gases in the selected category. Align the arrow with the
desired gas. Press SET to record your selection and return to the MAIN display.
The selected gas will be displayed on the screen.
* Pure Corrosive and Refrigerant gases are only available on S-Series instruments
that are compatible with these gases.
Note: Gas Select may not be available on units ordered with a custom gas or blend.
See pages 29 - 34 for a full list of gases in each category.

15
COMPOSER™
U P
DO W N
COMPOSER allows you to program and
save up to 20 custom gas mixes
containing 2 to 5 component gases
found in the gas lists (pages 32-39). The
> A dd M ix : 20 F r ee
CANCEL S E T
minimum resolution is 0.01%.
COMPOSER is accessed by selecting
COMPOSER User Mixes on the GAS
SELECT display.
Press SET when the arrow is aligned
with Add Mix.
Name the mix by pressing the UP and
DOWN buttons for letters, numerals
and symbols.
CHANGE CASE – Toggles the letter
case. Letters remain in selected case
until CHANGE CASE is pushed again.
UP DO W N N E X T
L E TTE R
Press SET to save the name.
C O M P O S E R M ix n a m e :
M y G a s
------ ˄
After naming the mix, press ADD GAS
and select the gas category and the
component gas.
Select the digit with arrow and adjust
B A C K /
C AN C EL
C HANG E
CASE S E T
the % with the UP and DOWN buttons.
Press set to save. Add up to 4 more
gases as needed. The total must equal
100% or an error message will appear.
GAS OPTNS allows you to adjust the
percentage of the constituents or
delete a gas from the mix. Gas mixes
cannot be adjusted after they have
E D IT
NA M E
ADD GA S
G A S
O P T N S
been saved.
C O M P O S E R M ix : M y GA S
0 . 00 % o f To t a l
B A C K /
C AN C EL
C HANG E
CASE S E T

16
˄
˄
˄
UP DO W N
S E L E C T
D I G IT
UP DO W N
S E L E C T
D I G IT
P e r ce n t of A ir :
50 . 00
P e r ce n t of A r A r gon :
30 . 00
B A C K /
CANCEL CLEAR S E T
B A C K /
CANCEL CLEAR S E T
UP DO W N
S E L E C T
D I G IT
E D IT
NA M E
ADD GA S G A S
O P T N S
P e r ce n t of H e H e liu m :
20 . 00
B A C K /
CANCEL CLEAR S E T
C O M P O S E R M ix : M y GA S
50 % A ir
30 % AR A r gon
20 % H e H e liu m
10 0 . 00 % To t a l
CANCEL S AV E
CR E A TE
N E W
C R E A TE
S I M IL A R
Once the mix has been saved, you may
press CREATE SIMILAR to compose an
additional mix based on the mix you
have just saved. This CREATE SIMILAR
option is not available after leaving this
C O M P O S E R USER M IX
M y G a s
HAS BEEN S AV E D
S ELE C T
screen.
Press CREATE NEW to add a completely
new mix.
M A IN M IX TU R E Press SELECT MIXTURE to bring the
custom mix onto the MAIN display.

17
COMMUNICATION SELECT
Access Communication Select by pressing
the button above RS232 COMM on the
Select Menu display.
UNIT ID
A
B AUD
19 200
Unit ID – Valid unit identifiers are the
letters A-Z and @. The identifier allows
you to assign a unique address to each
device so that multiple units can be
connected to a single RS-232 computer
port.
BACK M A IN Press UNIT ID. Use the UP and DOWN
buttons to change the Unit ID. Press SET to
record the ID. Press Reset to return to the
previously recorded Unit ID.
Any Unit ID change will take effect when
Communication Select is exited.
If the symbol @ is selected as the Unit
UNIT ID U P
C
C
DO W N ID, the device will enter streaming mode
when Communication Select is exited.
See RS-232 Communications (page 22) for
information about the streaming mode.
Baud – Both this instrument and your
computer must send/receive data at the
BACK RESET A S E T same baud rate. The default baud rate for
this device is 19200 baud.
Press the Select button until the arrow is
in front of Baud. Use the UP and DOWN
buttons to select the baud rate that
matches your computer. The choices are
38400, 19200, 9600, or 2400 baud.
B AUD DOWN U P
19200
Any baud rate change will not take effect
until power to the unit is cycled.
BACK S E T

18
>
MISCELLANEOUS
Miscellaneous is accessed by pressing the MISC button on the Select Menu display.
Next select either MISC1 or MISC2.
MISC1 will display as shown at left.
ZERO BAND refers to Display Zero Deadband.
Zero deadband is a value below which the display
ZE R O
B AND
P R E SS
AVG
L C D
F L O W
AVG 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
exist. Display Zero Deadband does not affect the
analog or digital signal outputs.
B A C K CONTRAST M A IN ZERO BAND can be adjusted between 0 and
6.3% of the sensor’s Full Scale (FS).
Press ZERO BAND. Then use SELECT to choose
the digit with the arrow and the UP and DOWN
buttons to change the value. Press SET to record
your value. Press CLEAR to return to zero.
Pressure Averaging and Flow Averaging may
UP
DO W N
0 . 0
S ELE C T be useful to make it easier to read and interpret
rapidly fluctuating pressures and flows. Pressure
and flow averaging can be adjusted between 1
(no averaging) and 256 (maximum averaging).
These are geometric running averages where
CANCEL CLEAR S E T the number between 1 and 256 can be
considered roughly equivalent to the response
time constant in milliseconds.
This can be effective at “smoothing” high
frequency process oscillations such as those caused by diaphragm pumps.
Press PRESSAVG.Then use SELECT to choose the digit with the arrow and the UP and
DOWN buttons to change the value. Press SET to record your value. Press CLEAR to
return to zero.
Press FLOW AVG. Then use SELECT to choose the digit with the arrow and the UP and
DOWN buttons to change the value. Press SET to
record your value. Press CLEAR to return to zero.
Setting a higher number will equal a smoother
UP
DO W N
11
CANCEL RESET S E T
display.
LCD CONTRAST: The display contrast can be
adjusted between 0 and 31, with zero being the
lightest and 31 being the darkest. Use the UP
and DOWN buttons to adjust the contrast. Press
SET when you are satisfied. Press CANCEL to
return to the MISC display.

19
C LE A R
1013 55 . 0
S TP /
N TP
D IA G
TE S T
R OTA TE
D IS P
MISC2 will display as shown at le ft. STP/NPT
refers to the functions that allow your
selection of standard temperature and
pressure conditions or normal temperature
and pressure conditions. This feature is
generally useful for comparison purposes to
other devices or systems using different STP
parameters.
The STP menu is comprised of the STP TEMP
BACK M A IN and STP PRESS screens.
STP TEMP allows you to select from 0 C, 0 F, K
or 0 R. The arrow position will automatically
default to the currently stored value.
The NTP menu is comprised of the NTP TEMP
and NTP PRESS screens.
Once a selection has been made and recorded
S TP
TE M P
S TP
P R E SS
M A IN
using the SET butt on, a change acknowledgement
message will be displayed on screen.
Selecting MAIN will revert screen to the Main
display. If the SET selection is already the
currently stored value, a message indicating
that fact will appear.
STP PRESS enables you to select from a menu
pressure settings. Use the UP/DOWN or PAGE
buttons to view the settings.
The arrow position will automatically default to the currently stored value.
Once a selection has been made and recorded using the SET button, a change
acknowledgement message will be displayed on screen.
Pressing SET again will revert screen to the Main display. If the SET selection is
already the currently stored value, a message indicating that fact will appear.
UP DO W N
S ELE C T
D IG IT
UP DO W N
S ELE C T
D IG IT
Te m p e r a t u r e : #C
25 . 0000
P r e ss u r e : P a A
B A C K /
C AN C EL
S E T
B A C K /
C AN C EL
C LE A R
S E T
STP TEMP Display STP PRESS Display

20
R8: AP Sig
7871
R9: Temp Sig
39071
R10: DP Side
9986
R11: DP Brdg
36673
R13: AP Brdg
36673
R16: Meter Func
199
R18: Power Up
32768
SCROLL
BACK MAIN
DIAG TEST: This diagnostic screen displays
the current internal register values, which
is useful for noting factory settings prior to
making any changes. It is also helpful for
troubleshooting with MATHESON customer
service personnel.
Select the DIAG TEST button from the MISC2
screen to view a list of select register values.
Pressing the SCROLL button will cycle the
display through the register screens. An
example screen is shown at left.
Press ROTATE DISP and SET to Inverted 180° if your device is inverted. The
display and buttons will rotate together.
DEVICE UNITS
Press DEVICE UNITS to access menus of
units of measure for each parameter (and
totalizer if so equipped).
U P
M a ss F lo w
DO W N
Scroll to the desired unit and press select.
V olu m e t r ic F lo w
P r e ss u r e
Te m p e r a t u r e
M a ss To t a liz e r
To t a liz e r Tim e
DONE S ELE C T
Once selected, you will see the message
shown below. Verify that all connected
devices expect the change.
See pages 35 and 36 for a full list of
available units.
U P
S CC M
S c m 3 / h
S m 3 / h
S m 3 / d
S in3 / m
S C F H
N m L / s
DO W N P A G E
PRESSING SET WILL
AFFECT DISPLAY
AND SERIAL VALUES
VERIFY CONNECTED
SERIAL DEVICES
EXPECT THE CHANGE
CANCEL S E T
C AN C EL
S E T