Siargo MF-HD Series User manual

Gas Flow Meters
MF-HD Series
With MEMS Thermal Mass Flow Sensing
VA.2
@ 2022 Siargo Ltd.
www.Siargo.com

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Gas Flow Meters
With MEMS Thermal Mass Flow Sensing
MFHD Series
User Manual
Document No. 07-2022-CMCD EN
Issue date: 2022.07
Revision: VA.2
Siargo Ltd.
3100 De La Cruz Boulevard, Suite 210
Santa Clara, CA 95054
USA
Tel: [phone]
Email: [email protected]om
© Copyright 2022 by Siargo Ltd.
Siargo Ltd. and its subsidiaries reserve the right to change the specifications and/or descriptions
without prior notice. For further information and updates, please visit www.Siargo.com.

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Attention !
Use with caution !
•Please carefully read this manual before operating this product.
•Do not open or modify any hardware which may lead to irrecoverable
damage.
•Do not use this product if you suspect any malfunctions or defection.
•This product is designated for city natural gas metering at the applicable
pressure.
•Cautions for the specified hazardous conditions. Do not weld online.
•Only the trained or qualified personnel shall be allowed to perform
product services.
•Be cautious for electrical safety, and even it operates at a low voltage,
any electrical shock might lead to some unexpected damages.
•The fluid to be measured should be clean and free of particles, as
debris or particles may be accumulated inside the flow channel
that may result in inaccuracy in metrology, clogging, or other
irrecoverable damage.
•Do not apply for any unknown or non-specified fluids that may
damage the product.
•Do not force the connection. If the thread is not the same as the pipeline,
user an adapter or contact the manufacture for the correct model.

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Table of Contents
1. Overview ......................................................................................................................................................5
2. Receipt / unpack of the products ...............................................................................................................6
3. Knowing the products.................................................................................................................................7
3.1 Product description.............................................................................................................................7
3.2 Power....................................................................................................................................................7
3.3 Mechanical dimensions.......................................................................................................................8
4. Installation ...................................................................................................................................................9
4.1 Battery installation .............................................................................................................................9
4.2 Connection to gas supply pipe ...........................................................................................................9
5. Basic operation..........................................................................................................................................12
5.1 Check the product specifications .....................................................................................................12
5.2 Check the gas supply system............................................................................................................12
5.3 Check the leakage .............................................................................................................................12
5.4 Display................................................................................................................................................12
5.5 Remote operation / Wireless data ...................................................................................................13
5.6 Pressure loss in LPG ..........................................................................................................................14
5.7 Digital communication .....................................................................................................................14
5.7.1 Power and data cable description................................................................................................14
5.7.2 RS485 Modbus communication protocol....................................................................................15
5.7.2.1 Hardware connection.....................................................................................................................15
5.7.2.2 Communication parameters ..........................................................................................................15
5.7.2.3 Frame..............................................................................................................................................16
5.7.2.4 Function codes................................................................................................................................16
5.7.2.5 Registers .........................................................................................................................................16
6. Product selection.......................................................................................................................................19
6.1 LPG .....................................................................................................................................................19
6.2 Other gases........................................................................................................................................19
7. Technical specifications ............................................................................................................................20
8. Technical notes for the product performance ........................................................................................21
8.1 Measurement principle .....................................................................................................................21
8.2 Precautions for the best performance of the product....................................................................21

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8.2.1 Particle contamination .................................................................................................................21
8.2.2 Product calibration........................................................................................................................21
9. Troubleshooting ........................................................................................................................................22
10. Warranty and Liability ..........................................................................................................................23
11. Service/order contact and other information.....................................................................................25
Appendix I: Meter evaluation via RS485 Modbus ..........................................................................................26
AI-1. Connect the meter to a PC...................................................................................................................26
AI-2. Software description............................................................................................................................26
Appendix II: Document history........................................................................................................................27

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1. Overview
All contact information can be found at the end of this manual.
This manual provides essential information for the operation of the MFHD series of battery-powered
gas flow meters for metering and management applications. The product performance,
maintenance, troubleshooting, and the information for product order, technical support, and repair
are also included.
In addition to the general-purpose flow metering, the MFHD series can be applied for utility gas
metering that is designed and manufactured with Siargo’s proprietary MEMS (micro-electro-
mechanical systems) thermal (D-thermal) sensing technology. The products offer mass flow
metering for gases with large dynamic ranges while having a low-pressure drop.
One of the key applications is the LPG fuels that are delivered in gas cylinders for the residents where
the natural gas pipeline is out of reach. The products provide better management of the cylinders
that can timely inform the users as well as the supplier for logistics and prevent supply shortage for
the users, while the suppliers would better manage their manufacture, inventory, and delivery
schedules. The current products are designed for the North American market where the LPG
cylinders are having a large capacity and the pressure regulators are pre-installed at the supply. The
product will meter the usage, detect the possible leakage and alert the user as well as the supplier
via wireless cloud data management.
Certification for safety proof for hazardous gases is in progress and will be updated once it is
completed.

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2. Receipt / unpack of the products
Upon receipt of the products, please check the packing box before the dismantlement of the packing
materials. Ensure no damages during shipping. If any abnormality is observed, please contact and
notify the carrier who shipped the product and inform the distributors or sales representatives if the
order is not placed directly with the manufacturer; otherwise, the manufacturer should be notified.
For any further actions, please refer to the return and repair section in this manual.
If the packing box is intact, proceed to open the packing box, and you shall find the product (either
the meter or the sensor formality per the actual order). There are two models of serial products with
different flow ranges. One is 1” in diameter and another one is ¾” in diameter. Make sure the product
is what you have ordered.
Please check immediately for the integrity of the product and
the power and data cable. If any abnormal is identified, please
notify the distributor/sales representative or manufacturer as
soon as you can. If any defects are confirmed, an exchange
shall be arranged immediately via the original sales channel.
This user manual shall also be included in the packing box or
via an online request for an electronic version. In most cases,
this manual shall be made available to the customer before
the actual order.

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3. Knowing the products
3.1 Product description
Figure 3.1: MF-HD part description
3.2 Power
The product is powered by lithium-ion batteries, D-Cell (19AHr). For general purpose flow
applications, one battery shall be sufficient for the applications, and under the normal data
acquisition, the battery life should be not less than 3 calendar years. In case heavy data
communication is required, the products also offer an alternative two-battery option for which
one battery is used for metrology that allows the meter to work continuously without the need
to change for over 5 years or longer. For fuel cylinder operation, the battery can last for over 10
years or the specified lifetime of the battery. Another battery will only supply power to data
communication, and it will be easy to access and be changed when the warning is sent to the user.
For the batteries, only a fully safety certified and lifetime guaranteed lithium-ion battery of D-
Cell can be used to ensure the performance and meter field operation time. In case the lithium-
ion battery is prohibited for transportation. Contact the manufacturer for the solutions.
Change of the battery for the communication operation would be dependent on the frequency
of the data transmission. Consult the manufacturer or local dealer for recommendations.
Meter body
Battery cover
(communication)
LCD display
Inlet with NPT
thread
Outlet
Flow direction

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3.3 Mechanical dimensions
Figure 3.2: Dimensions of MF19HD
Figure 3.3: Dimensions of MF25HD

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4. Installation
4.1 Battery installation
The meter is powered by dual lithium-ion batteries. One battery is for metrology and is pre-installed
at the factory, which allows a minimum of 5 years of operation depending on the working conditions.
For fuel cylinder metering, the battery can last for 10 years or the specified battery lifetime.
For general purpose flow applications, one battery has opted. The battery chamber is located at the
meter front lower part. It is recommended a 3.6V D-cell lithium-ion battery that has the certification
for electronic instrument safety proof. Please note: that only one battery chamber is accessible
via the front cover.
(Note: in some areas, because of the restriction of the lithium-ion battery by the freight carrier, please
contact the local sales representative for a solution. If the pre-installed battery is missing, the battery
installed at the front battery chamber can also supply the power to the meter. The battery life will then be
shorter depending on operation settings.)
Figure 4.1: Battery installation
4.2 Connection to gas supply pipe
Do not open or alter any part of the product, except the battery chamber, which would lead to
malfunction and irrecoverable damage that will forfeit the terms of the warranty.
The product at the time of shipment is fully inspected for product quality and meets all safety
requirements. Additional safety measures during the installation should be applied. This includes but
is not limited to leakage verification procedures, standard EDS (electrostatic discharge) precautions,
DC voltage precautions, and heavy-duty precautions. Other tasks, such as calibration, part
Battery chamber
for communication
Use a screw driver to open the front
battery chamber cover, Install the
battery inside the battery chamber,
and then close the chamber cover
tight.
The battery is recommended to be a
D-Cell, 19 AH lithium-ion battery with
safety proof, such as Tadiran 4930 or
TITUS ER26500.
Interface, digital
RS485 Modbus

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replacement, repair, and maintenance, must only be performed by trained personnel. Upon request,
the manufacturer will provide the necessary technical support and/or training for the personnel.
Any action to alter the physical integrity will forfeit the terms of the warranty and cause the liability
for any damages thereafter.
The product is preferable to be installed horizontally. Flow direction should be aligned with the arrow
mark on the meter body. If the flowing fluid may have particles or debris, a filter is strongly
recommended to be installed upstream of the meter.
Please follow the following steps to complete the installation:
a) Upon opening the package, the product's physical integrity should be inspected to ensure no visual
damage.
b) Before installing the product, please ensure that the pipe debris or particles or any other foreign
materials are completed removed.
c) Cautions during installation:
(i) It is preferably first to install the inlet end of the meter and then the outlet end of the meter;
To ensure the measurement accuracy, an upstream straight pipe of length no less than 10DN
and a downstream straight pipe of length no less than 5DN should be in place.
Figure 4.2: Installation recommendation
(a) 90-degree elbow or T-piece (b) 2x90 degree elbows
Figure 4.3: Installation recommendation

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(ii) If there is a requirement for different pipe sizes either upstream or downstream, the size of
the pipe diameters should be larger than that of the selected meters. Please see the details
below:
(c) 3x90 degree elbows, 3 dimensions (d) Pipe diameter reduction
(e) Pipe diameter expansion (f) with upstream control valve
(iii) During installation, please make sure no foreign materials (such as water, oil, dirt, particles,
etc.) fall into the pipe.
d) Slowly open the valves at both ends of the pipeline, and the meter should then start to measure
the flow in the pipeline.
e) Completion of the installation.
Cautions
a) Don't try to alternate any build-in part of the product.
b) Use only the battery with safety proof.
c) Release all the installation stresses so that no stresses will be exerted on the product.
d) The product should avoid strong electromagnetic interference sources nearby or periodic
mechanical shocks to its body or pipeline.
e) Slowly open/close valves to prevent abrupt pulse flow impact, damaging the product.

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5. Basic operation
5.1 Check the product specifications
Before starting to use this product, check the product specifications found in this manual or the basic
information located on the product's back panel.
The product information from this manual may be model specified. In particular, the pressure rating
must not be higher than the system pressure of the gas to be measured, and the flow range should
also be within the specified ones. In most cases, a high full-scale ranged meter for the low flow rate
measurement often results in erroneous data. The gas to be measured must also be consistent with
that specified by the product.
5.2 Check the gas supply system
For the product's best performance, it is advised that the gas to be measured must be clean and free
of particles or other foreign materials. An upstream filter with a proper pore size would be an
example of safe usage of the product from particle contamination. Please consider the actual
application requirements for the filter specification, such as pressure loss, gas conditions, etc. Before
releasing the gas to pass through the product, check the tubing again to avoid any abnormal, tighten
the tubing fittings, and verify the measurement gas flow direction.
5.3 Check the leakage
Check leakage before any measurement. If needed, pressurized nitrogen or air can be used for the
leakage check.
5.4 Display
Figure 5.1: LCD symbol illustration.

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Table 5.1: Symbols description
Row A
Displays the totalized flowrate in m3or SCF. May display the gas
tariff for a pre-paying meter when the corresponding MENU is
selected.
Row B
Displays instant flowrate, temperature, date, and time
For pre-pay meter or remote charge meter. When balance is due,
the symbol will flash. (reserved for future product upgrade)
Valve status (reserved for future product upgrade).
Battery status. MPS –is the battery for communication.
Communication signal indicator.
Data transmitting in progress
Indicate LPG gas is being metered. It will go out with airflow.
Alarm indicator, when any alarms are triggered.
User information, when the corresponding MENU is entered.
(Reserved for future product upgrade)
Settings, when the corresponding MENU is entered. (Reserved for
future product upgrade)
Available tools, when the corresponding MENU is entered.
(reserved for future product upgrade)
Reserved for energy metering.
5.5 Remote operation / Wireless data
The meter supports BT LE, NB-IoT, or other remote data options.
The remote user can execute the following functions. This portion shall be updated with customer
feedback.
•Read the meter data
•Setting the parameters
•Receive the alarms
•Others TBD

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5.6 Pressure loss in LPG
Figure 5.2: Pressure loss
5.7 Digital communication
5.7.1 Power and data cable description
Table 5.2: Data wire assignment.
Socket Cable
Figure 5.3: Socket and Cable
Wire
Color
Definition
1
Brown
Power supply (5~16 Vdc)
2
White
RS485B (-)
3
Blue
GND, ground
4
Black
RS485A (+)
5
Gray
N.C.
MFHD19, G6/G10
MFHD25, G16
MFHD19, G6/G10
MFHD25, G16

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5.7.2 RS485 Modbus communication protocol
The digital communication protocol is based on standard Modbus RTU Half-plex mode. A master (PC
or PLC) can communicate with multiple slaves (the current product) for data exchange and
communication parameter configuration. Refer to Appendix I for the specific connection for the
current product. The digital converter provided by Siargo allows you to plug and play with the meter
for its basic functions. For experienced users, the followings are the explanation of the digital
interface.
5.7.2.1 Hardware connection
The hardware layer is TIA/EIA-485-A, shown below, for which the product (MF-HD) is a slave.
5.7.2.2 Communication parameters
The PC UART communication parameters are listed in the following table.
Parameters
Protocol
RTU
Baud rate (Bits per second)
9600 bps
Start bits
1
Data bits
8
Stop bits
1
Even/Odd parity
None
Bits period
104.2 µsec
Bytes period
1.1458 msec
Maximum data length
20
Maximum nodes
247

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5.7.2.3 Frame
The frame function is based on the standard Modbus RTU framing:
Start_bits
Address
Function codes
Data
CRC
Stop_bits
T1-T2-T3-T4
8 bit
8 bit
N 8 bit (20≥n≥0)
16 bit
T1-T2-T3-T4
Start_bits: 4 periods bit time, for a new frame.
Address: The address can be set from 1 to 255 except for 157 (0x9d). 0 is the broadcast address.
Function codes: Define the product (MF5700)'s functions/actions (slaves), either execution or response.
Data: The address of the register, length of data, and the data themselves.
CRC: CRC verification code. The low byte is followed by the high byte. For example, a 16-bit
CRC is divided into BYTE_H and BYTE_L. In the framing, the BYTE_L will come first, then
followed by the BYTE_H. The last one is the STOP signal.
Stop_bits: 4 periods bit time, for ending the current frame.
5.7.2.4 Function codes
The Modbus function codes applied for the product are the sub-class of the standard Modbus
function codes. These codes are used to set or read the registers of the product:
Code
Name
Functions
0x03
Read register
Read register(s)
0x06
Set single register
Write one single 16-bit register
0x10
Set multiple registers
Write multiple registers
5.7.2.5 Registers
The product (MF5700) has multiple registers available for the assignment of the various functions. With
these functions, the user can obtain the data from the products, such as product address and flow rates from
the registers, or set the product functions by writing the corresponding parameters.
The currently available registers are listed in the following table, and the registers may be customized upon
contacting the manufacturer. Where R: read; W: write-only; W/R: read and write.
Note: At the time of shipping, the write protection function is enabled except for address and baud
rate. Once the user completes the register value change, the write protection will be automatically
enabled once again to prevent incidental data loss.

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Functions
Description
Register
Modbus reference
Address
Product address (R/W)
0x0081
40130 (0x0081)
Serial number
Serial number (R)
0x0030
40130 (0x0030)
Alarm
Alarm events (R)
0x0036
40130 (0x0036)
Flow rate
Current flow rate (R)
0x003A~0x003B
40059 (0x003A)
Accumulated flow
Accumulated or totalized flow rate (R)
0x003C~0x003E
40061 (0x003C)
GCF
Gas correction factor (R/W)
0x008B
40140 (0x008B)
Offset calibration
Offset reset or calibration (W)
0x00F0
40241 (0x00F0)
Write protection
Write protection of selected parameters (W)
0x00FF
40256 (0x00FF)
The detailed information of each register is described below: A: available; N: not available
Flowmeter address
0x0081
Write
A
Read
A
Description
Address of the product
Value type
UINT 16
Notes
Values from 1 to 255 except for 157 (0x9d). 0 is the broadcast address.
SN, Serial number
0x0030
Write
N
Read
A
Description
Series Number of the product, SN
Value type
UINT8 (12 bits)
Notes
SN= value(0x0007), value(0x0008),….,value (0x000C);
Receiving 12 bytes as: 2A 47 37 41 45 49 30 32 30 35 38 2A , the corresponding Serial
Number is *G7AEI02058*.
Flowmeter address
0x0036
Write
N
Read
A
Description
Alarm events
Value type
UINT 16
Notes
Bit0：battery low; Bit1：Flow rate out of range
Bit2：Hardware error; Bit3：Reverse flow observed
Bit4：Sensor error; Bit8：Register error
Bit12：Battery disconnected.
Current flow rate
0x003A ~ 0x003B
Write
N
Read
A
Description
Current flow rate
Value type
UINT 16
Notes
Flow rate = [Value (0x003A)*65536 + value (ox003B)]/1000
e.g.: for a flow rate of 20.340 SLPM, the user will read “0” from register
0x003A and “20340” from register 0x003B, therefore
Current flow rate = (0*65536+20340)/1000 = 20.340

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Accumulated flow rate
0x003C ~ 0x003E
Write
N
Read
A
Description
Accumulated or totalized flow rate
Value type
UINT 32 + UINT 16
Notes
V1 = Value (0x003C) * 65536 + Value (0x003D)
V2 = Value (0x003E)
Accumulated flow rate = (V1 * 1000 + V2)/1000
e.g.: for an accumulated flow rate of 3452.245 SCF, the user will read “0” from
register 0x003C; “3452” from register 0x003D, and “245” from register 0x003E.
Then, the accumulated flow rate = ((0 + 3425)*1000 + 245)/1000=3425.245.
GCF or K factor
0x008B
Write
A
Read
A
Description
The gas conversion factor for using with gas is different from calibration gas or
adjusting a system deviation.
Value type
UINT 16
Notes
The air (default) is 1000, normally read from register 0x008B.
The product will disable this function with write protection once the
metering gas is confirmed with the proper GCF. For a specific GCF value,
please contact the manufacturer.
Offset calibration
0x00F0
Write
A
Read
N
Description
Reset or calibrate the offset
Value type
UINT 16, Fixed value 0xAA55
Notes
To reset or calibrate the offset, write 0xAA55 to register 0x0027.
When you execute this function, make sure there is NO flow in the flow
channel.
Write protection
0x00FF
Write
A
Read
N
Description
Write protection disabler for a set value to a specific register.
Value type
UINT 16, Fixed value 0xAA55
Notes
This function is enabled at the time of product shipment. To enable the write
function of a specific parameter, such as GCF, offset, or accumulated flow rate,
the user needs to send 0xAA55 to the register 0x00FF, and then the write
function will be enabled (write protection is disabled). After the write
execution is completed, the firmware will automatically re-enable the write
protection.
Only Address and Baud rate will not be write-protected.

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6. Product selection
Please refer to the following model guide for product selection and order.
6.1 LPG
DN
Mechanical connection
Min flowrate (m3/h)
Max flowrate (m3/h)
MF19GD G6
19
NPT 3/4” or BSPT 3/4”
0.06
10
MF25GD G10
25
NPT 1” or BSPT 1”
0.10
16
6.2 Other gases
MF HD - - - -
Note: For X and Y values, please contact the manufacturer. For the flow range please consult
the following table.
DN
Mechanical connection
Min flowrate
Max flowrate
MF19GD G6
19
NPT 3/4” or BSPT 3/4”
0.24 m3/h
4 SLPM
24 m3/h
400 SLPM
MF25GD G10
25
NPT 1” or BSPT 1”
0.36 m3/h
6 SLPM
36 m3/h
600 SLPM
Note: Air, N2, Ar, and O2 have the same flow ranges.
Gas: A –air, N2, Ar, O2; X –others
Output: B –RS485 Modbus / BTLE; Y –others
Mechanical connection: N –NPT; B –BSPT
Full scale flow rate: 24 / 36 m3/h (400 / 600 SLPM)
Model number: 19 –19mm; 25 –25mm