Instruction manual
LIQUI-FLOW mini series
Digital Liquid Mass Flow Meters
Doc. no.: 9.17.065C Date: 26-07-2011
ATTENTION:
Please read this instruction manual carefully before installing and operating the instrument.
Not following the guidelines could result in personal injury and/or damage to the equipment.
Disclaimer
Even though care has been taken in the preparation and publication of the contents of this manual, we do not assume
legal or other liability for any inaccuracy, mistake, mis-statement or any other error of whatsoever nature contained
herein. The material in this manual is for information purposes only, and is subject to change without notice.
Bronkhorst High-Tech B.V.
July 2011
Symbols
Important information. Discarding this information could cause injuries to people or damage to the
Instrument or installation.
Helpful information. This information will facilitate the use of this instrument.
Additional info available on the internet or from your local sales representative.
Receipt of equipment
Check the outside packing box for damage incurred during shipment. Should the packing box be damaged, then the
local carrier must be notified at once regarding his liability, if so required. At the same time a report should be
submitted to your distributor.
Carefully remove the equipment from the packing box. Verify that the equipment was not damaged during shipment.
Should the equipment be damaged, then the local carrier must be notified at once regarding his liability, if so required.
At the same time a report should be submitted to your distributor.
Before installing a LIQUI-FLOW mini instrument it is important to read the attached labels and check:
- Flow rate
- Fluid to be measured
- Pressure
- Output signal
- Temperature
Do not discard spare or replacement parts with the packing material and inspect the contents for
damaged or missing parts.
Refer to chapter 6 about return shipment procedures.
Equipment storage
The equipment should be stored in its original packing in a cupboard warehouse or similar. Care should be taken not
to subject the equipment to excessive temperatures or humidity.
9.17.065 page 2
Warranty
The products of Bronkhorst High-Tech B.V. are warranteed against defects in material and workmanship for a period
of three years from the date of shipment, provided they are used in accordance with the ordering specifications
and the instructions in this manual and that they are not subjected to abuse, physical damage or
contamination. Products that do not operate properly during this period may be repaired or replaced at no charge.
Repairs are normally warranteed for one year or the balance of the original warranty, whichever is the longer.
See also paragraph 9 of the Conditions of sales:
http://www.bronkhorst.com/files/corporate_headquarters/sales_conditions/en_general_terms_of_sales.pdf
The warranty includes all initial and latent defects, random failures, and undeterminable internal causes.
It excludes failures and damage caused by the customer, such as contamination, improper electrical hook-up, physical
shock etc.
Re-conditioning of products primarily returned for warranty service that is partly or wholly judged non-warranty may
be charged for.
Bronkhorst High-Tech B.V. prepays outgoing freight charges when any party of the service is performed under
warranty, unless otherwise agreed upon beforehand. However, if the product has been returned collect to Bronkhorst
High-Tech B.V., these costs are added to the repair invoice. Import and/or export charges, foreign shipping
methods/carriers are paid for by the customer.
9.17.065 page 3
Table of contents
1 SCOPE OF THIS MANUAL............................................................................................................................... 5
1.1 Introduction.......................................................................................................................................................... 5
1.2 References to other applicable documents..........................................................................................................5
2 STARTING UP ................................................................................................................................................ 6
2.1 Check properties ..................................................................................................................................................6
2.2 Rated pressure test inspection.............................................................................................................................6
2.3 Check piping .........................................................................................................................................................6
2.4 Install system........................................................................................................................................................ 6
2.5 Leak check ............................................................................................................................................................7
2.6 Electrical connection ............................................................................................................................................7
2.7 Analog / digital operation..................................................................................................................................... 7
2.8 Multi-functional switch operation........................................................................................................................ 8
2.9 Purging ................................................................................................................................................................. 8
2.10 Zeroing.................................................................................................................................................................. 9
2.11 Calibration ............................................................................................................................................................9
2.12 Supply pressure ....................................................................................................................................................9
2.13 Product description ..............................................................................................................................................10
2.14 Measuring principle..............................................................................................................................................10
2.15 Model key............................................................................................................................................................. 11
3 BASIC OPERATION ........................................................................................................................................ 12
3.1 General .................................................................................................................... .............................................12
3.2 Analog operation..................................................................................................................................................12
3.3 Manual interface: micro-switch and LED’s...........................................................................................................12
3.4 Basic RS232 FLOW-BUS operation........................................................................................................................12
3.5 Basic parameters and properties .........................................................................................................................13
3.5.1 Introduction.......................................................................................................................................................... 13
3.5.2 Basic parameters ..................................................................................................................................................14
4 ADVANCED OPERATION................................................................................................................................ 15
4.1 Reading and changing instrument parameters ....................................................................................................15
4.1.1 Introduction.......................................................................................................................................................... 15
4.1.2 Identification ........................................................................................................................................................15
4.1.3 Fluid information..................................................................................................................................................16
4.1.4 Auto zeroing ......................................................................................................................................................... 16
4.1.5 Changing default control mode............................................................................................................................ 17
4.1.6 Display filter.......................................................................................................................................................... 17
4.1.7 Disabling micro switch..........................................................................................................................................18
4.2 Using mass flow meters on different fluids or under different conditions ..........................................................18
4.2.1 Stored calibration fluids .......................................................................................................................................18
4.2.2 Conversion factor calculation using Fluidat software ..........................................................................................18
5 TROUBLESHOOTING AND SERVICE ................................................................................................................ 19
5.1 General .................................................................................................................... .............................................19
5.2 LED indication....................................................................................................................................................... 19
5.3 Troubleshooting summary general ......................................................................................................................19
5.4 Service ..................................................................................................................................................................20
6 REMOVAL AND RETURN INSTRUCTIONS ....................................................................................................... 21
9.17.065 page 4
1 Scope of this manual
1.1 Introduction
This manual covers the LIQUI-FLOW mini series mass flow meters for micro fluidic flow. An example of the
instrument is shown in the picture below. This manual includes product information, installation instructions,
operation, maintainance and troubleshouting.
LIQUI-FLOW mini instruments are one of the smallest micro fluidic Mass Flow Meters (MFM) of its kind. The very
compact instruments with dimensions 20 x 40 x 60 mm are capable of measuring ultra low flow rates in ranges
starting from 1.5…30 mg/h up to 12…600 mg/h, based on water. The straight, duplex steel sensor tube (W1.4462)
has an internal volume of less than 1 mm
pressure rating of max. 1200 bar (17400 psi) the MFM is suited for HPLC systems. The instruments are equipped
with a microprocessor-based printed circuit board, offering high accuracy and excellent temperature stability. The
RJ45 connection is used for power supply and for both analog and digital (RS232) communication.
3
and operates on the thermal measuring principle. Due to its high
1.2 References to other applicable documents
Instructions:
- LIQUI-FLOW mini Quick Installation Guide (document nr. 9.17.066)
- Operation instructions digital instruments (document nr. 9.17.023)
- RS232 interface with FLOW-BUS for digital instruments (document nr. 9.17.027)
Technical drawings :
- Hook-up diagram LIQUI-FLOW mini RS232 + Analog I/O (document nr. 9.16.097)
- Dimensional drawing (document nr. 7.05.823)
These documents are available on: http://www.bronkhorst.com/en/downloads
or can be applied for at our local sales & service representatives
9.17.065 page 5
2 Starting up
1500
2.1 Check properties
Before installing your Mass Flow Meter it is important to
read the attached labels and check:
- Flow rate
- Pressure
- Fluid to be measured
- Output signal
- Temperature
2.2 Rated pressure test inspection
Each LIQUI-FLOW mini instrument is pressure tested to at least 1.5 times
the working pressure of the process conditions stipulated by the customer.
Each instrument is helium leak tested to at least 2
outboard.
⋅
10-9 mbar l/s Helium
Output
A – 0…5 Vdc
B – 0…10 Vdc
F – 0…20 mA
G – 4…20 mA
Pressure testing label
The tested pressure is stated on the instrument with a RED COLOURED sticker. Before installation, make
sure that the test pressure is in accordance with normal safety factors for your application.
If there is no Pressure Testing Sticker on the device or if the test pressure is incorrect, the instrument
should not be mounted in the process line and be returned to the factory.
2.3 Check piping
For reliable measurement always make sure the fluid stream
is clean.
Use filters to assure a particle-free liquid stream.
Recommended pore-size: 2 µm.
If back flow can occur, a downstream filter is recommended too.
2.4 Install system
Install the LIQUI-FLOW mini Meter in the line, in accordance with
the direction of the FLOW arrow. The arrow for flow direction is
indicated on the body of the instrument.
Make sure to use 10-32 UNF fittings (ferrules/nuts) and tubing
suitable for the maximum applied system pressure. Only use 1/16”
tubing with a straight and clean cut without burrs to ensure leak
tightness. Preferrably deburr the tubing prior to installation. A new
ferrule connection must be made for each new adapter to ensure
leak-tightness and minimum dead volume, due to variances in the
adapter dimensions.
Tighten the 10-32 UNF fittings according to the instructions of the
supplier of the fittings.
9.17.065 page 6
Location:
Install the instrument on a stable position and assure that mechanic vibration, heat source influence
and draft are reduced to a minimum. The instruments are insensitive to mounting position.
2.5 Leak check
Check the system for leaks before applying (fluid) pressure. Especially if toxic, explosive or other
dangerous fluids are used!
2.6 Electrical connection
Electrical connections must be made with standard cables or
according to the applicable hook-up diagrams. These documents
can be found at:
http://www.bronkhorst.com/en/downloads
Please note that LIQUI-FLOW mini instruments are dustproof according to IP40, implying that the
electronics housings and electrical connections do not offer any protection against moist
environments.
Converter RJ45/DB9
7.03.376
RJ45
The instruments contain electronic components that are susceptible to damage by electro static
discharge. Proper handling procedures must be taken during installation, removing and connecting the
electronics.
The instruments described in this manual carry the CE-mark and are complient with the EMC
requirements. However compliance with the EMC requirements is not possible without the
use of proper cables and connector/gland assemblies. Bronkhorst High-Tech B.V. recommends the use
of their standard cables. These cables have the right connectors and if loose ends are used, these will be
marked to prevent wrong connection. When using other cables, cable wire diameters should be
sufficient to carry the supply current and voltage losses must be kept as low as possible. When in doubt:
contact your distributor.
When connecting the system to other devices (e.g. to PLC), be sure that the integrity of the shielding is
not affected. Do not use unshielded wire terminals.
2.7 Analog / digital operation
2.7a Analog/Local operation
Connect the Mass Flow Meter to the power supply/readout
unit using an RJ45 cable connector, with converter to 9-pin
sub-D.
Power:
+15...+24 Vdc
Analog output:
0…5Vdc / 0…10Vdc
0…20mA / 4…20mA
9.17.065 page 7
2.7b Digital operation
For this procedure see description for RS232
operation. RS232 connection cable 7.03.426
enables to use (free) Bronkhorst tooling
programs for Windows.
2.8 Multi-functional switch operation
Using the two colored LEDs and the switch on the instruments,
several actions can be monitored and started. The green LED
is used for status indication. The red LED is used for errors/
warnings/messages. The switch can be used to start several
actions, such as auto-zero, restore factory settings and businitialization actions, if applicable. See specific zero-procedure
below for more details.
2.9 Purging
Purge the system with a non-reactant liquid prior to use. Expecially in systems for use with corrosive or
reactive fluids, purging for at least 30 minutes with a non-reactant liquid is absolutely necessary before
use. Purge the system until all gas bubbles have disappeared and avoid the creation of gas bubbles in
the system through expansion or dead volumes. The measurement stability is greatly influenced by the
presence of gas bubbles in the system. After use with corrosive or reactive fluids, complete purging is
also required before exposing the system to air.
Waste fluid:
Make sure not to spill fluid on the instrument while
purging. Always keep the sensor exterior dry.
Status LED
Multi-functional switch
Error/Warning LED
Warm-up time:
Let LIQUI-FLOW mini warm-up for at least 30 minutes for best accuracy.
During warm-up period, fluid pressure may either be on or off.
9.17.065 page 8
2.10 Zeroing
The zero-point of each instrument is factory adjusted. If so required the zero point may be readjusted over RS232 or by means of using the micro switch. Refer to section 4.1.4 for auto-zeroing
procedure over RS232. Procedure for zeroing by micro switch:
♦ Warm-up, pressure up the system and fill the instrument according to the process
conditions.
♦ Make sure no flow is going through the instrument by closing valves near the instrument.
♦ The sensor signal should be stable; any unexpected sensor instability may be caused by leaks
or trapped gas bubbles.
♦ Press micro switch and hold it. After a short time the red LED will go ON and OFF, then the
green LED will go ON. At that moment release the micro switch.
♦ The zeroing procedure will start at that moment and the green LED will blink fast. The
zeroing procedure waits for a stable signal and saves the zero. If the signal is not stable,
zeroing will take long and the nearest point to zero is accepted. The procedure will take
approximately 10 seconds.
♦ When the indication is showing 0% signal and the green indication LED is burning
continuously again, the zeroing action was succesful.
2.11 Calibration
Each LIQUI-FLOW mini instrument is factory calibrated. Bronkhorst High-Tech certifies that all instruments meet the
rated accuracy. Calibration is performed using measurement standards traceable to the standards of the Dutch
Metrology Institute (VSL). Calibration certificates are included in the shipment. When operated properly (clean liquid,
no pressure shocks, no vibrations, no thermal shocks, etc), regular maintenance is not required. However, periodical
inspection, recalibration or verification of the accuracy may be subject to individual requirements of the end-user.
2.12 Supply pressure
It is recommended to turn on power before applying pressure on the instrument and to switch off
power after removing pressure.
Turn on fluid supply gently. Avoid pressure shocks and bring the instrument gradually up to the level of
the actual operating conditions. Also switch off fluid supply gently.
9.17.065 page 9
2.13 Product description
A LIQUI-FLOW mini flow meter consists of a thermal mass flow sensor with a digital electronic PC-board for sensor
enhancement and communication. The sensor consists of a straight capillary with two heat resistant wires wound
around it. The measuring principle is explained briefly in section 2.14 below. The sensor signal is measured and
digitized directly at the sensor by the PC-board. The internal software (firmware) processes the signal (linearisation
and amplification) to the desired signal level, which is then translated to the desired output. Each instrument is
equipped with an analog and a digital interface, which can be used simultaneously.
Digital operation adds a lot of extra features (compared to analog operation) to the instruments, such as direct
reading at readout/control module or host computer, identification (serial number, model number, device type, user
tag) and adjustable instrument settings.
2.14 Measuring principle
The liquid flow sensor operates on a principle of heat transfer by sensing the temperature difference along a heated
section of a capillary tube. The temperature difference sensed by the upstream and downstream temperature sensors
on the capillary depends on the amount of heat absorbed by the fluid flow. The temperature sensors are part of a
bridge circuit, as seen in the figure below. The measured imbalance of the bridge, caused by the flow in the capillary is
linearised to the mass flow rate and amplified to the desired signal level.
V
signal
Thermal sensor in a bridge configuration
The transfer function between mass flow and sensor signal can be described by the equation:
cKV Φ⋅⋅=
mpsignal
with:
= sensor signal
V
signal
= specific heat of the fluid
c
p
K = constant factor
= mass flow
Φ
m
From this formula it can be concluded that for each different fluid (with heat capacity c
) a certain sensor signal
p
represents a different mass flow. Using accurate fluid data and a conversion factor it is possible to predict the mass
flows for liquids other than water.
9.17.065 page 10
2.15 Model key
Code Instrument type
Code Instrument type
LM02 Liquid flow meter 30...600 mg/h, PN1000-1200
Code Communication
A RS-232 + analog I/O
AANN
-
A A A
Code
A
B
F
G
Output
0...5 Vdc
0...10 Vdc
0...20 mAdc sourcing
4...20 mAdc sourcing
Code Supply
D + 15...24 Vdc
Inlet Outlet
Inlet0
1
9
N N-
-
Setpoint
0...5 Vdc
0...10 Vdc
0...20 mAdc sinking
4...20 mAdc sinking
Adapter
Outlet0
10-32 UNF female
1
1/8" OD compression type
9
other specify
Seal Material
0 None (metal seal)
Code Sensor code
NNA Selected by factory
-
A
NNA
9.17.065 page 11
3 Basic operation
3.1 General
A LIQUI-FLOW mini instrument must be powered with +15…24 Vdc. The instrument can be operated by means of:
• Analog interface (0…5 Vdc; 0…10 Vdc; 0…20 mA or 4…20 mA)
• Digital RS232 interface (connected to a COM-port on 38400 Baud)
Switching between digital operation (in RS232 mode) and analog operation is done by setting the parameter IOStatus.
See section 4.1.5 for more details.
3.2 Analog operation
At analog operation following signals are available:
• measured value (analog output)
• setpoint (analog input, not used)
• valve voltage (not used)
The type of installed analog interface (0…5 Vdc; 0…10 Vdc; 0…20 mA or 4…20 mA) can be found in the model key of
the instrument. Refer to paragraph 2.15.
When operating the instrument through the analog interface it is possible to connect the instrument
simultaneously to RS232 for reading/changing parameters (e.g. settings or fluid selection).
3.3 Manual interface: micro-switch and LED’s
By means of manual operation of the micro push-button switch some important actions for the instrument can be
selected/started. These options are available in both analog and digital operation mode.
These functions are:
- reset (instrument firmware-program reset)
- auto-zeroing
- restore factory settings (in case of accidently changing of the settings)
The LED’s on top of the instrument can also be used for manual operation of some options. The green LED will indicate
in what mode the instrument is active. The red LED will indicate error/warning situations.
For details see “manual interface” in Operation Instructions Digital Instruments (document nr.
9.17.023, Chapter 10)
3.4 Basic RS232 FLOW-BUS operation
Digital operation adds a lot of extra features (compared to analog operation) to the instruments.
Such as:
- Up to eight selectable fluids (calibration settings for high accuracy)
- direct reading at readout/control module or host computer
- testing and self diagnosis
- identification (serialnumber, modelnumber, device type, user tag)
- adjustable minimal and maximal alarm limits
- (batch) counter
RS232 FLOW-BUS communication can be used for operating your instrument using the Bronkhorst FlowDDE server
application.
Physical layer and communication protocol are detected automatically upon reception of messages.
These messages must be sent using the correct combination of physical layer and communication
protocol. After every power-up the communication detection mode is active.
9.17.065 page 12
Dynamic Data Exchange (DDE) provides the user a basic level of inter process communication between Windows
applications. FlowDDE is a DDE server application. Together with a client-application, either self-made or with a
SCADA-program from 3rd-parties, it is possible to create an easy way of data exchange between the flow controller
and a Windows application. For example, a cell in Microsoft Excel could be linked to the measured value of the flow
controller and when the measured value changes, it will be automatically updated in the Excel spreadsheet.
Examples of DDE client applications: FlowPlot, FlowView, MS-Office, LabView, Intouch, Wizcon.
The FlowDDE server also offers a lot of test facilities and user adjustable settings for efficient communication with the
connected flow/pressure meter or controller.
How to setup a DDE link with FlowDDE is described in the help-file of the FlowDDE application.
Programming examples are available for making applications in: Visual Basic, LabView and Excel.
FlowDDE parameter numbers:
Reading/changing parameter values via FlowDDE offers the user a different interface to the instrument.
Besides the application name: ‘FlowDDE’ there is only need of:
• topic, used for channel number: ‘C(X)’
• item, used for parameter number: ‘P(Y)’
A DDE-parameter number is a unique number in a special FlowDDE instruments/parameter database and not the
same as the parameter number from the process on an instrument.
Node-address and process number will be translated by FlowDDE to a channel number.
FlowDDE and other Bronkhorst applications are available at the Bronkhorst download site:
http://www.bronkhorst.com/en/downloads
For more information regarding communication through an RS232 interface, see document nr.
9.17.027: RS232 interface with FLOW-BUS for digital instruments.
3.5 Basic parameters and properties
3.5.1 Introduction
Every instrument parameter has its own properties. These properties are given in a table as shown:
Type Access Range FlowDDE FLOW-BUS
[type] RW [x]…[y] [FB] [proc]/[par]
Type
Unsigned char 1 byte character
Unsigned char[x] x byte array (string)
Unsigned int 2 byte unsigned integer
Float 4 byte floating point
Access
R The parameter is read-only
RW The parameter can be read and write
RW The parameter can only be written when the Init Reset parameter is set to 64. See section
4.1.1 for more details.
Range
Some parameters only accept values within a certain range:
[x] Minimal value of the range.
[y] Maximal value of the range.
9.17.065 page 13
FlowDDE
Parameter number in FlowDDE. Check section 3.4 for more information.
FLOW-BUS
Process and parameter number to address parameters using the FLOW-BUS protocol.
[Pro] FLOW-BUS process number
[Par] FLOW-BUS parameter number
Check document 9.17.027, “RS232 interface with FLOW-BUS protocol”, for detailed information.
3.5.2 Basic parameters
Measured Value (Measure)
Type Access Range FlowDDE FLOW-BUS
Unsigned int R 0…41942 8 1/0
The measured value indicates the amount of mass flow metered by the instrument. The signal of 0...100% will be
presented in a range of 0...32000. The maximum signal to be expected is 131.07 %, which is: 41942.
Measured Value (Fmeasure)
Type Access Range FlowDDE FLOW-BUS
Float R ±1E-10… ±1E+10 205 33/0
Floating point version of variable measure (see 3.5.2). The user can read-out the measured value in the capacity and
capacity unit for which the instrument has been calibrated. These settings depend on variables: capacity, capacity unit,
sensor type and capacity 0%. Fmeasure is a read-only float on (FLOW-BUS) proc 33, par 0. Value is calculated as
follows:
Fmeasure = ((Measure / 32000) * (Capacity - Capacity0%)) + Capacity0%
Fmeasure: proc 33, par 0
Measure: proc 1, par 0
Capacity: proc 1, par 13
Capacity0%: proc 33, par 22
The value is in units as described in parameter capacity unit (proc 1, par 31).
Control Mode
Type Access Range FlowDDE FLOW-BUS
Unsigned int RW 0…18 12 1/4
The Control mode is used to select different functions of the instrument. The following modes are available:
Value Mode Instrument action
0 DIGITAL_INPUT not used
1 ANALOG_INPUT not used
9 CALIBRATION_MODE Calibration mode enabled
After power-up the control mode will always be set to DIGITAL_INPUT or ANALOG_INPUT, depending on customer’s
requirement.
9.17.065 page 14
4 Advanced operation
4.1 Reading and changing instrument parameters
4.1.1 Introduction
All parameters described in this chapter have influence on the behaviour of the mass flow meter. Please
be aware that wrong settings can disorder the output.
To avoid unintential changes of these parameters, these parameters are locked. To unlock these
parameters use set parameter “Init Reset” to “UN_LOCKED”
Init Reset
Type Access Range FlowDDE FLOW-BUS
Unsigned char RW 82/64 7 0/10
The Init Reset parameter is used to ‘unlock’ advanced parameters for writing. This parameter can be set to the
following values:
Value Mode Instrument action
82 LOCKED Advanced parameters are
read-only
64 UN_LOCKED Advanced parameters are
writeable and readable.
This parameter is always set to “LOCKED” at power-up.
4.1.2 Identification
Serial number
Type Access Range FlowDDE FLOW-BUS
Unsigned char[20] R - 92 113/3
This parameter consists of a maximum 20-byte string with instrument serial number for identification.
Example: “M0202123A”
BHT Model number
Type Access Range FlowDDE FLOW-BUS
Unsigned char[14] R - 91 113/2
Bronkhorst High-Tech instrument model number information string.
Firmware version
Type Access Range FlowDDE FLOW-BUS
Unsigned char[5] R - 105 113/5
Revision number of firmware. Eg.: “V1.12”
Usertag
Type Access Range FlowDDE FLOW-BUS
Unsigned char[13] RW - 115 113/6
User definable alias string. Maximum 13 characters allow the user to give the instrument its own tag name.
It is advised here to limit the name up to 7 characters when using E-7000 readout and control modules.
These modules can display the tag name of an instrument only up to 7 characters. Eg.: “Room1s6”
9.17.065 page 15
Customer model
Type Access Range FlowDDE FLOW-BUS
Unsigned char[16] RW - 93 113/4
Digital instrument manufacturing configuration information string. This string can be used by Bronkhorst High-Tech to
add extra information to the model number information.
4.1.3 Fluid information
The following parameters give information about the selected fluid range.
Fluid name
Type Access Range FlowDDE FLOW-BUS
Unsigned char[10] RW - 25 1/17
Fluid name consists of the name of the fluid. Up to 10 characters are available for storage of this name.
Fluid unit
Type Access Range FlowDDE FLOW-BUS
Unsigned char[7] R - 129 1/31
The Fluid unit can be read by parameter ‘capacity unit’. This parameter contains the unit in maximal 7 characters.
Fluid Capacity (@100%)
Type Access Range FlowDDE FLOW-BUS
Float R ±1E-10… ±1E+10 21 1/13
Capacity is the maximum value (span) at 100% for direct reading in sensor base units.
Fluid Capacity (@0%)
Type Access Range FlowDDE FLOW-BUS
Float R ±1E-10… ±1E+10 183 33/22
This is the capacity zero point (offset) for direct reading in sensor base units.
4.1.4 Auto zeroing
To start the auto zero-procedure two parameters should be written:
Control Mode
Type Access Range FlowDDE FLOW-BUS
Unsigned int RW 0…18 12 1/4
Check section 3.5.2 for available control modes.
Calibration Mode
Type Access Range FlowDDE FLOW-BUS
Unsigned int RW 9 58 115/1
Value Mode Instrument action
0 IDLE Idle
9 AUTO_ZERO Auto-zeroing
255 ERROR Idle
9.17.065 page 16
Procedure:
Step 1: Set Control Mode to CALIBRATION_MODE (9)
Step 2: Set Calibration Mode to AUTO_ZERO (9)
Step 3: Check Calibration Mode,
IDLE Auto-zeroing succeeded
AUTO_ZERO Auto-zeroing active
ERROR Auto-zeroing failed
4.1.5 Changing default control mode
Instruments are delivered with either analog or digital signal as default, depending on customer’s requirement. After
every (power on) reset the instrument will return to its default control mode.
The default control mode can be changed with the following parameter:
IOStatus
Type Access Range FlowDDE FLOW-BUS
Unsigned char RW 0…255 86 114/11
Bit 6 [7..0] represents the former analog jumper.
1 = default control mode is analog
0 = default control mode is digital
Procedure for changing default digital operation to default analog operation:
• Read IOStatus
• Add 64 to the read value
• Write IOstatus
Procedure for changing default analog operation to default digital operation:
• Read IOStatus
• Subtract 64 from the read value
• Write IOstatus
])400[( xOR
])400[( xAND
4.1.6 Display filter
The output signal of a LIQUI-FLOW mini instrument (measured value) is filtered. The filter has dynamic behaviour:
when a change in sensor signal is detected, the measured value will be less filtered than when the sensor signal is
constant and stable. There are two filter constants: Static Display Factor and Dynamic Display Factor. These two
factors can be transformed into time constants using the following formula:
factor
−
τ
cycletime
1
⋅=
factor
The measured value is filtered with a first order low pass filter with a filter time constant between these two τ values.
Dynamic Display Factor
Type Access Range FlowDDE FLOW-BUS
Float RW 0 … 1.0 56 117/1
Static Display Factor
Type Access Range FlowDDE FLOW-BUS
Float RW 0 … 1.0 57 117/2
CycleTime
Type Access Range FlowDDE FLOW-BUS
Unsigned char R 0…255 52 114/12
Note: The unit of parameter CycleTime is 10ms. Example: value 0.2 means 2ms
9.17.065 page 17
4.1.7 Disabling micro switch
It is possible to disable the Micro Switch on top of the instrument. This can prevent undesired use of this button.
Disabling the micro switch can be performed with the following parameter:
IOStatus
Type Access Range FlowDDE FLOW-BUS
Unsigned char RW
Bit 3 [7..0] is used to disable the micro switch.
1 = micro switch disabled
0 = micro switch enabled
Procedure to disable the micro switch:
• Read IOStatus
• Add 8 to the read value
• Write IOstatus
Procedure to enable the micro switch:
• Read IOStatus
• Subtract 8 from the read value
• Write IOstatus
0…255 86 114/11
4.2 Using mass flow meters on different fluids or under different conditions
4.2.1 Stored calibration fluids
LIQUI-FLOW mini instruments with digital pc-boards allow storage of max. 8 calibration curves for various fluids or
process conditions. Fluidsets can digitally be selected when the instrument is hooked-up by RS232 to a computer,
using (Bronkhorst) software tools.
4.2.2 Conversion factor calculation using Fluidat software
Bronkhorst High-Tech B.V. gathered the physical properties of over 600 fluids in a database called FLUIDAT.
Application software, such as FLOW CALCULATIONS, enables the user to calculate accurate conversion factors, not
only at 20°C/1 atm but at any temperature/pressure combination, both for gases and for liquids.
Apply to your distributor for more details of this software.
Check FLUIDAT® on http://www.fluidat.com
FLUIDAT® is a collection of routines to calculate physical properties of gases and liquids. These routines
are made available at the FLUIDAT® on the Net website.
9.17.065 page 18
5 Troubleshooting and service
5.1 General
For a correct analysis of the proper operation of a flow meter it is recommended to remove the unit from the process
line and check it without applying fluid supply pressure. In case the unit is dirty or clogged, this can be ascertained
immediately by loosening the fittings and inspecting visually.
Energizing or de-energizing of the instrument indicates whether there is an electronic failure. After that, fluid pressure
is to be applied in order to check behaviour. If there should be suspicion of leakage, do not disassemble the sensor for
inspection but contact your local distributor for service or repairs.
5.2 LED indication
The red LED on the instrument gives error or warning information.
z
z
z
Red LED Time Indication
Off Continuously No error
On Continuously Critical error message
A serious error occurred in the instrument
Instrument needs service before further use
For more information check the instruction manual for digital communication 9.17.023 at
http://www.bronkhorst.com/en/downloads/instruction_manuals/
5.3 Troubleshooting summary general
Symptom Possible cause Action
No output signal No power supply Check power supply and hook-up
Check cable connection and hook-up.
Check status of LED’s
(see manual 9.17.023)
Cable damaged or hooked-up
incorrectly
PC-board damaged due to long lasting
shortage and/or high-voltage peaks
No or too low inlet pressure Increase inlet pressure
Open shut-off at inlet and outlet
Supply pressure too high, or differential
pressure across meter too high
Sensor / capillary failure Return to factory
Maximum output signal Sensor / capillary failure Return to factory
Output signal much lower than
setpoint signal or desired flow
Incorrect type of liquid or too low inlet
pressure
Oscillation / Signal noise Trapped gas bubbles in the system Purge the system and make sure no
Pressure regulator of supply pressure is
Small flow indication when
flow is definetly zero
oscillating or wrong sized
Increased zero reading without flow
caused by raised zero-point
No digital communication Occupied or wrong bus address Change address with software
Check and compare signals at both ends
of cable.
Return to factory
Reduce supply pressure
Test instrument on conditions for which
it was designed
leaks or dead volumes are present
Replace pressure regulator
Perform an auto-zero action
9.17.065 page 19
5.4 Service
For current information on Bronkhorst High-Tech and service addresses please visit our website:
Do you have any questions about our products? Our Sales Department will gladly assist you selecting the right product
for your application. Contact sales by e-mail:
For after-sales questions, our Customer Service Department is available with help and guidance.
To contact CSD by e-mail:
No matter the time zone, our experts within the Support Group are available to answer your request immediately or
ensure appropriate further action. Our experts can be reached at:
+31 573 45 88 39
Þ http://www.bronkhorst.com
} sales@bronkhorst.com
} support@bronkhorst.com
9.17.065 page 20
6 Removal and return instructions
Instrument handlings:
• Purge fluid lines
• Remove instrument from line
• Insert the instrument into a plastic bag and seal the bag
• Place the bag in an appropriate shipping container
Add documentation:
• Reason of return
• Failure symptoms
• Contaminated condition
• Declaration on Contamination form: 9.17.032
When returning material, always describe the problem and if possible the work to be done, in a covering letter.
It is absolutely required to notify the factory if toxic or dangerous fluids have been metered with the instrument!
This to enable the factory to take sufficient precautionary measures to safeguard the staff in their repair department.
Take proper care of packing, if possible use the original packing box; seal instrument in plastic, etc.
Contaminated instruments must be dispatched with a completely filled in 'declaration on contamination form'.
Contaminated instruments without this declaration will not be accepted.
Note:
If the instruments have been used with toxic or dangerous fluids the customer should pre-clean the instrument.
Important:
Clearly note, on top of the package, the customer clearance number of Bronkhorst High-Tech B.V., namely:
NL801989978B01
If applicable, contact your distributor for local arrangements.
The declaration on contamination form is available at the Bronkhorst download site:
http://www.bronkhorst.com/en/downloads/safety_information_for_returns.pdf
9.17.065 page 21
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