Dwyer Instruments TFP-LI Technical Document

Manual F-20-TF-L
June 2008
Revision 1
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MODEL TFP-LI
MODEL TFM-LI
MODEL TFP-LP
MODEL TFM-LP
Flow Sensors and Flow Meters For Liquids
Installation Manual & Operating Instructions
READ THIS MANUAL COMPLETELY BEFORE ATTEMPTING TO CONNECT
OR OPERATE YOUR FLOW SENSOR. FAILURE TO DO SO MAY RESULT
IN INJURY TO YOU OR DAMAGE TO THE FLOW SENSOR.
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F-20-TF-L, pg. 2 of 30
T A B L E O F C O N T E N T S
A. Introduction .........................................................................................3
1. Unpacking..................................................................................................3
2. Product Overview And Principle Of Operation..............................................3
B. Installation ........................................................................................... 5
1. General Considerations ..............................................................................5
2. Mounting The Flow Sensor Or Flow Meter ..................................................6
3. Tubing Connections ....................................................................................7
4. Electrical Connections .................................................................................8
a) Overview ...........................................................................................9
b) Connecting A Cable Assembly.................................................................9
c) Electrical Connections – Voltage Output Units (TFP-LI & TFM-LI Series) .....10
d) Electrical Connections – Units With Both Voltage & Pulse Outputs
(TFP-LP & TFM-LP Series).........................................................................11
e) Using a 0-5VDC Output Power Adapter Package....................................12
C. Operation .......................................................................................... 13
1. Start-Up ...................................................................................................13
2. Entrapped Air or Gas ................................................................................13
3. Flow Readings ..........................................................................................13
a) 0-5VDC Analog Outputs .......................................................................14
b) Pulse Outputs .....................................................................................14
c) Units with an Integral Display.................................................................14
4. Operating at Flow Rates Outside the Calibrated Flow Range.......................15
a) Flows Above the Maximum Rated Flow...................................................15
b) Flows Below the Minimum Rated Flow ....................................................16
5. Zero Adjustments ......................................................................................16
6. Recalibration ............................................................................................16
7. Calibrating Units for different Liquids.........................................................19
D. Maintenance And Product Care............................................................ 19
1. General....................................................................................................19
2. Cleaning and Flushing ..............................................................................20
3. Returning Units For Repair Or Recalibration ...............................................20
E. Specifications ..................................................................................... 21
F. Dimensions ........................................................................................ 23
G. Connector Pin And Wire Color Cross Reference .....................................27
H. Trouble Shooting Guide ......................................................................28
I. Warranty ........................................................................................... 30
J. Contacting Dwyer ............................................................................... 30
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F-20-TF-L, pg. 3 of 30
A. Introduction
1. Unpacking
All sensors are suitably packaged to prevent damage during shipping. If
external damage is noted upon receipt of the package, please contact
the
shipping company
immediately. Dwyer Instruments is not liable for damage
to the device once it has left the manufacturing premises.
Open the package from the top, taking care not to cut too deeply into the
package. Remove all the documentation and contents. Take care to remove
all the items and check them against the packing slip. The products should
also be checked for any concealed shipping damage. If any shortages or
damage is noted, please contact the shipping company and/or Dwyer
Instruments to resolve the problem.
Typical Contents of Box
Sensor, Calibration Certificate & Instruction Manual
(Model TFP-LP shown, other models similar).
CAUTION: Take care not to
drop your sensor or subject it to
sudden impact. Read the installation section of this manual before
providing power or tubing connections to the unit. Any damage
caused by improper installation or careless handling will not be
repaired under warranty (see limited warranty on page 30 for
more details).
2. Product Overview and Principle of Operation
TF Series Flow Meters and Flow Sensors for liquids are capable of
measuring flows as low as 13-100 ml/min or as high as 1.0-10.0 l/min.
Highly repeatable results are achieved using a patented Pelton Turbine
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Wheel flow sensor design. This proven design minimizes zero drift while
maintaining fast response and linear outputs with virtually no maintenance.
Patented technology measures flow using a miniature turbine wheel similar
in size to a U.S. dime (16 mm diameter, 0.75 mm thick). The micro-turbine
wheel is supported on a very small sapphire shaft that is held in position by
two sapphire bearings. The micro-turbine assembly is so light that it virtually
floats in the liquid. This relieves force on the bearings and almost eliminates
wear.
As flow passes through the flow sensor, a precision machined nozzle directs
the fluid onto the very small teeth of the micro-turbine wheel. This causes the
wheel to spin at a speed proportional to the flow rate.
The micro-turbine wheel has alternating white and black sections evenly
spaced on one side of the wheel. An infrared light beam is directed onto the
wheel. As the wheel rotates the infrared beam is reflected off each white
section. The reflected beam is detected by a phototransistor that converts the
reflections into electrical pulses. As the wheel spins faster the pulse rate
increases. Processing circuitry provides analog and/or pulse output that are
linearly proportional to the flow rate
When the wheel stops (under zero flow conditions), no pulses are
generated. Consequently, zero drift is not possible and zero adjustments are
never required.
Every unit is supplied with a calibration certificate detailing the results
obtained during calibration. Units are calibrated using deionized water as
the reference media. Flowing liquids with different specific gravities or
viscosities may affect the calibration.
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F-20-TF-L, pg. 5 of 30
B. Installation
CAUTION: Do not flow any gas through a liquid flow sensor.
This may damage the micro-turbine assembly and void the
warranty. Do not exceed the pressure, temperature or power
operating ranges detailed in the Specifications section of this
manual. Dwyer Instruments shall not be liable for any damage or
injury caused by incorrect operation of their products.
1. General Considerations
It is recommended that a safety shut-off valve be installed upstream of
(before) the sensor.
All wetted parts should be checked for compatibility with the liquid to be
used. If there are any incompatibilities e.g. highly corrosive liquid, then the
unit may be damaged or fail prematurely. Such damage will not be
repaired under warranty.
Units should be installed in a clean, dry environment with an ambient
temperature that is as stable as possible. Avoid areas with strong magnetic
fields, strong air flows or excessive vibration.
If the liquid to be used may contain particles larger than 25 microns then a
filter (25 microns or less) should be installed upstream of (before) the unit.
The required differential press (or pressure drop across the unit) decreases
exponentially with decreases in flow rate.
Pressure Drop vs. Percentage of the Full Scale
Rated Flow (may vary ±10% of indicated psid)
0
2
4
6
8
10
12
10 20 30 40 50 60 70 80 90 100
% of rated flow
Delta P psid
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Delta P Bar
100-1000 ml/min Units
All Other Ranges
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To calculate the pressure drop at a certain flow rate use the formula
PD = (YourFlow / MaxFlow)2xPDmax
PD = Pressure drop at YourFlow.
YourFLow = flow rate (ml/min or l/min)
MaxFlow = 100% rated flow for the sensor (in same units as YourFlow)
PDmax = Pressure drop at 100% rated flow (see chart above)
If the pressure available for the flow sensor is BELOW the pressure drop at
the required flow then flow through the unit will not be possible.
For example: You have a sensor with a 50-500ml/min flow range and want
to know the pressure drop (or minimum differential pressure required) at
300ml/min. According to the chart above, the pressure drop at 100% of
flow is approx 10psi. Using the formula above:
PD = (300 / 500)2x 10 = 3.6 psid
Therefore, at 300ml/min the minimum required differential pressure for this
unit is 3.6 psid. This means that if the available pressure is below 3.6psid
then flow through the unit may not be possible.
Pressure drop through a system is cumulative. If the total pressure drop
across all the components in a system exceeds the minimum pressure
available then flow will not be possible.
For example: A system has a pressure of 30-40psi. There are several
components and the sum of their pressure drops at the required flow rate is
32psid. If the system is operating at 30psi flow would not be possible as the
total of the pressure drops would be greater than the pressure available.
The system will only operate if the system pressure is above 32psi.
If there is any possibility that there may be bubbles or entrapped gas in the
system then the outlet tubing should be elevated above the inlet port. This
will enable any gas that may become entrapped in the unit to escape (see
section C2 for details of how to remove entrapped air or gas).
2. Mounting the Flow Sensor or Flow Meter.
The TF Series of Flow Sensors and Flow Meters have no particular
installation requirements so may be mounted in any convenient position.
It is recommended that units be fixed to a suitable substrate with #4 screws
using the two mounting holes provided.
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F-20-TF-L, pg. 7 of 30
Mounting The Sensor
(Mounting hardware not included with sensor)
3. Tubing Connections
CAUTION: DO NOT FLOW ANY GAS THROUGH A LIQUID
FLOW SENSOR OR FLOW METER. THIS WILL DAMAGE THE
MICRO-TURBINE ASSEMBLY AND VOID THE WARRANTY.
All tubing must be clean and without crimps, burrs or scratches.
Only use the fittings factory installed on the unit. If the fittings are removed
the calibration of the unit may be effected and leaking may occur. If
different fittings are required please contact Dwyer Customer Service for
assistance.
When connecting the sensor to the tubing a wrench should be used to stop
the fitting rotating in the sensor body. Take care not to over tighten the
fittings or leaking may occur.
Connecting and tightening the Fittings
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F-20-TF-L, pg. 8 of 30
CAUTION: DO NOT over tighten the fittings into the sensor
body. Excessive force may damage the sensor body and will
NOT be repaired under warranty.
The flow direction for the unit is clearly marked on the label. Do not reverse
the flow direction or the unit will not function.
Close Up of Label Showing Flow Directions
(All models similar)
For the best results, precautions should be taken to minimize the amount of
turbulence in the flow stream. Avoid valves, fittings, curves in the tube, and
changes in the internal diameter or any other restrictions close to the inlet of
the sensor. The tubing ID should be as large as possible and preferably not
smaller than the ID of the fittings installed on the sensor.
For 0.2-2.0 L/min units a 10 cm straight length of tube before the sensor is
recommended. For higher flow range units (0.5-5.0 L/min and 1.0-10.0
L/min), a 20 cm straight length of tubing before the sensor is recommended.
If this is not possible it is recommended that straight lengths between all
connections on the inlet side of the sensor are as long as possible and 90
degree fittings (with a large enough ID) are used instead of curves in the
tubing.
4. Electrical Connections
CAUTION: Incorrect wiring may cause severe damage to the
unit. Applying an AC voltage (115VAC or 230VAC) directly to
the unit will cause damage. Read the following instructions
carefully before making any connections.
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F-20-TF-L, pg. 9 of 30
a) Overview
The TFP-LP and TFM-LP series provide a 0-5VDC and pulse output
proportional to the flow rate. This output may be connected to a display,
data acquisition system or voltmeter.
The TFP-LI and TFM-LI feature an integral display that provides a local flow
reading. These units also have a 0-5VDC analog output available. If
required, this may be connected to another display, data acquisition system
or voltmeter.
A stable D.C. power supply is required to operate the unit. The voltage and
current requirements depend on the configuration of the unit. Full details
may be found in the Specifications section of this manual.
Connecting wires should be as short as possible to avoid voltage drops.
Twisted 2 pair conductor cable should be used if the length of the power
wires is to be longer than 1 meter.
Units are supplied with an integral 4 pin connector. Connections to the unit
are made using a mating cable assembly or power adapter package as
detailed in the following sections (parts 4.b to 4.e of this manual). A
connector pin and wire color cross reference may also be found in
Appendix G (Page 27) of this manual.
b) Connecting the Cable Assembly
The connector on the end of the cable assembly should be pushed into the
mating socket on the sensor taking care to ensure that it is the correct way
up.
Connecting the Cable Assembly
(All models similar)
Electrical Connections are made to the cable assembly as detailed in the
following sections.
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F-20-TF-L, pg. 10 of 30
c) Electrical Connections – Voltage Output Units (TFP-LI &
TFM-LI Series)
The cable assembly should be connected to the sensor as detailed in section
4(b) above. Power should not be applied to the sensor until all the
connections have been made and checked. Electrical connections should be
made as follows:
Wiring Schematic For Voltage Output Units.
The RED wire should be connected to the Positive of the power source.
The BLACK wire should be connected to the Negative ( Ground ) of the
power source.
The WHITE wire provides the signal output and should be connected to the
positive terminal of the display, data acquisition system or voltmeter with an
impedance of greater than 2500Ω(Ohms).
The GREEN wire (if present) is NOT used
CAUTION: Avoid high voltage static discharges to any of the
connections. Do not short the input/output signal wires or allow
them to contact the power wires at any time. DAMAGE WILL
RESULT!
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F-20-TF-L, pg. 11 of 30
d) Electrical Connections –Units with Both Voltage and Pulse
Outputs (TFP-LP & TFM-LP Series)
The cable assembly should be connected to the sensor as detailed in section
4(b) above. Power should not be applied to the sensor until all the
connections have been made and checked.
Wiring Schematic For Voltage and Pulse Output.
The RED wire should be connected to the Positive of the power source.
The BLACK wire should be connected to the Negative ( Ground ) of the
power source.
The WHITE wire provides the signal output and should be connected to the
positive terminal of the display, data acquisition system or voltmeter with an
impedance of greater than 2500Ω(Ohms).
The GREEN wire (“T” option only) is the pulse output and should be
connected to the Positive terminal of the data acquisition system with an
impedance of greater than 10KΩ(Ohms).
The PULSE and VOLTAGE output may be monitored simultaneously.
CAUTION: Avoid high voltage static discharges to any of the
connections. Do not short the input/output signal wires or allow
them to contact the power wires at any time. DAMAGE WILL
RESULT!
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F-20-TF-L, pg. 12 of 30
e) Using a 0-5VDC Output Power Adapter Package.
An optional 0-5VDC Output Power Adapter Package is available for use
with the TF Series. This consists of a power source (115VAC or 230VAC)
and cable assembly with pig-tail (soldered wire) ends for the signal output.
This should be assembled as shown in the following diagram.
Connecting the Power Adapter to the Flow Sensor
(All other models similar)
Electrical connections to the cable assembly should be made as follows:
YELLOW WIRE: This provides the 0-5VDC signal output and should be
connected to the positive terminal of the display, data acquisition system or
voltmeter with an impedance of greater than 2500Ω(Ohms).
GREEN WIRE: For Pulse output units the green wire provides the pulse
output and should be connected to the positive terminal of the data
acquisition system with an impedance of greater than 10KΩ(Ohms).
WHITE WIRE: This is the signal negative and should be connected to the
negative (ground) terminal of the voltmeter, display or data acquisition
system.
CAUTION: Avoid high voltage static discharges to any of the
connections. Do not short the output signal wires or allow them to
contact the power wires at any time. DAMAGE WILL RESULT!
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F-20-TF-L, pg. 13 of 30
C. Operation
CAUTION: USE WITH LIQUIDS ONLY. FLOWING GAS OR AIR
THROUGH YOUR FLOW SENSOR WILL DAMAGE THE MICRO-
TURBINE ASSEMBLY. THIS TYPE OF DAMAGE WILL NOT BE
REPAIRED UNDER WARRANTY.
1. Start Up
Before applying power to the unit check all tubing and electrical
connections. Once correct installation is verified switch on the power.
2. Entrapped Air or Gas
There may be a lot of air or gas trapped in your sensor after installation.
This will usually escape the unit when flow (within the range of the unit) is
first started.
CAUTION: The system should be primed with liquid and flow
started gradually. This will prevent trapped air or gas from being
forced through the sensor at a high velocity that may damage the
sensor.
If gas remains entrapped in the unit it may be necessary to elevate the outlet
tubing above the inlet of the sensor. This should enable the trapped gas to
escape the unit. The sensor may be returned to its original position once all
the gas has escaped.
If elevating the outlet tubing does not work, block or pinch the outlet tube
whilst there is flow in the system. After approximately 5 seconds, release the
restriction to allow normal flow. Doing this will build up pressure in the flow
path that when released will help remove the entrapped gas. Repeat this
until the entrapped gas is removed from the unit.
3. Flow Readings
TFP-LP and TFM-LP Series sensors provide a 0-5VDC and pulse output
proportional to the flow rate.
The TFP-LI and TFM-LI Series feature an integral display that provides a local
flow reading and a 0-5VDC analog output.
Each flow sensor is factory calibrated for a specific flow range. The flow
range is shown on the unit’s label and calibration certificate. Units are
calibrated using deionized water as the reference media.
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F-20-TF-L, pg. 14 of 30
a) 0-5VDC Analog Outputs
By monitoring the voltage output signal it is possible to determine the flow
rate of the liquid. Units are configured so that an output signal of 5.0VDC is
provided when the maximum flow (i.e. Full Scale flow) is passing through
the unit. The output signal is linear and scalable enabling calculation of flow
rates within the sensor’s range. For example:
For a flow range of 50-500ml/min:
At 500ml/min the output signal would be 5VDC
If the output signal were 3.5VDC then the flow rate would be:
500 ÷ 5 × 3.5 = 350ml/min
If the maximum flow rate is exceeded non-linear and inaccurate readings
will result.
b) Pulse Outputs
By monitoring the Pulse output frequency it is possible to determine the flow
rate of the liquid. The pulse frequency for maximum flow through the unit
(i.e. full scale flow) is detailed on the calibration certificate. This differs from
unit to unit. This output is approximately linear and scalable within the
sensor’s range. For example:
For a flow range of 1.0-10.0l/min:
The calibration certificate gives the following:
At 10.0l/min the pulse output signal is 312Hz
At 5.0l/min the pulse output signal is 150Hz
At 2.0l/min the pulse output signal is 58Hz
If the output signal were 120Hz then the flow rate would be:
5.0 ÷ 150 × 120 = 4.0 l/min (using the closest calibration point)
c) Units With an Integral Display
The TFP-LI and TFM-LI Series feature an integral 3 ˝ digit LCD display. This is
configured to read in ml/min for flow ranges up to 50-500 ml/min and in
l/min for all other flow ranges. The display will only operate if power is
applied to the unit.
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Flow readings may be taken directly from the display or by monitoring the
0-5VDC analog output provided by using a cable assembly or power
adapter package (see above).
LCD Flow Display
(TFM-LI Series Shown, other models similar)
4. Operating at Flow Rates Outside the Calibrated Flow Range
CAUTION: If the flow through the unit exceeds 120% of the
maximum rated (full scale) flow the unit may be damaged. This
type of damage will not be repaired under warranty.
Flow measurement is only accurate within the calibrated flow range for the
unit. This is detailed on the calibration certificate. The unit will still operate, to
some degree, outside this flow range.
Results obtained when operating outside the specified range of the unit are
not accurate but may be considered repeatable.
a) Flows Above the Maximum Rated Flow.
If the flow rate is above the maximum rated (or full scale) flow, the unit will
still operate and provide an output signal proportional to the flow rate.
Flows must not exceed 120% of the maximum rated flow or the unit may be
damaged.
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F-20-TF-L, pg. 16 of 30
b) Flows Below the Minimum Rated Flow.
Signal outputs may be obtained at flow rates below the minimum specified
for your unit. The amount of flow that may be measured below the minimum
specified varies from unit to unit.
5. Zero Adjustments
It is impossible for there to be any zero drift so zero adjustments are never
required.
6. Recalibration
The calibration of the flow sensor may be easily verified using empirical
methods.
It should be noted that the use of empirical methods outside a certified
calibration laboratory is subject to inaccuracy and error. These methods
should only be used to gain an indication of a sensor’s performance. Please
contact Dwyer Customer Service if accurate, certified recalibration is
required.
A typical empirical calibration check may be carried out as follows:
Carefully adjust the flow rate so that the maximum output signal is obtained.
With the flow rate constant, liquid flowing through the unit should be
gathered in a container over a timed interval. The total volume flowed over
the timed period should then be measured using a measuring cylinder. The
actual flow rate (in the same units as the flow sensor calibration certificate)
may then be calculated. The actual maximum flow rate should then be
compared to the specified maximum flow rate to determine the error in
calibration. For example:
For a flow range of 20-200ml/min with a 0-5VDC output:
With a constant flow and constant 5VDC output the actual volume
measured over 30 seconds was 102ml.
Therefore the actual flow rate is:
(102 / 30) x 60 = 204ml/min
The error is therefore 204 – 200 = 4ml/min or 2%
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A second empirical check should be made at a flow rate below the
maximum for the unit e.g. at 50% of full scale. The calculated percentage
error at this flow should then be compared to the error at maximum flow. If
there is a big difference in the percentage errors then the flow signal is no
longer linear and the unit may be damaged (consult Dwyer Customer
Service).
Once it has been determined that the linearity is still acceptable and the
error in flow reading at maximum flow has been calculated, there are 3
options:
i.) Minor adjustments to actual calibration of the flow sensor may be made
by turning the gain potentiometer on the side of the unit. For example:
For a unit with a flow range of 13-100ml/min and a
0-5VDC output:
With a constant flow and constant 5VDC output the actual volume
measured over 60 seconds was 103ml.
The correct voltage output for a flow of 103 ml/min is:
(5/100) x 103 = 5.15 V
With the flow at a constant 103 ml/min the gain potentiometer
should be carefully adjusted so that a voltage output reading of
5.15 V is obtained.
If the unit cannot be suitably adjusted please contact Dwyer Customer
Service. Pulse outputs are not adjustable.
Adjusting the Gain Potentiometer Using a Flat Head Screwdriver
(TFP-LP Series shown, other models similar)
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F-20-TF-L, pg. 18 of 30
ii.) Adjust the scaling endpoints in the display or data acquisition system. For
example:
For a flow range of 50-500ml/min with a 0-5VDC output:
With a constant flow and constant 5VDC output the actual volume
measured over 60 seconds was 405ml.
Therefore the actual flow rate is:
(405 / 60) x 60 = 405ml/min
The display or data acquisition system may now be configured as
follows:
0 VDC = Zero flow
5VDC = 405ml/min
iii.) Apply the error factor to each flow reading taken. For example:
For a flow range of 0.2-2.0l/min connected to a display:
With a constant flow rate of 2.0 l/min on the display, the actual
volume measured over 20 seconds was 0.7l
Therefore the actual flow rate is:
(0.7 / 20) x 60 = 2.1 l/min
The error is therefore 2.1 – 2.0 = 0.1 l/min or 5%
If the display shows an uncorrected flow rate of 1.4 l/min then :
Corrected flow rate = Uncorrected flow rate + error
Corrected flow rate = 1.4 + 5% = 1.47 l/min
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F-20-TF-L, pg. 19 of 30
7. Calibrating Units for Different Liquids
The TF Series for liquids will operate with most translucent liquids subject to
compatibility of the wetted parts. Best results are obtained with low viscosity
(less than 10 centistokes) liquids. For information regarding higher viscosity
liquids, contact Dwyer Customer Service.
Units are calibrated with deionized water as the reference media. Using
other liquids will affect the calibration. The amount of calibration error will
depend on the characteristics of the liquid being flowed.
The error in flow reading (or calibration) should be calculated and utilized
as detailed in section 6 above.
D. Maintenance and Product Care
1. General
CAUTION: Do not disassemble your flow meter or flow sensor
for any reason. If the unit appears to be malfunctioning please
contact Dwyer Customer Service.
The TF Series of flow sensors require no periodic maintenance if used within
the recommended specifications.
The next recommended recalibration date is stated on the calibration
certificate supplied with the unit. Please contact Dwyer Customer Service for
further information.
Inlet filters should be periodically checked and cleaned / replaced as
necessary.
Regularly check all electrical and process connections for damage or
deterioration.
If the sensor is to be stored, keep both the inlet and outlet ports sealed.
Do not store a sensor with any chemical other than water (or air) inside it
over an extended period of time. Prolonged exposure to chemicals other
than water may lead to precipitation or corrosion.
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F-20-TF-L, pg. 20 of 30
2. Cleaning and Flushing
If there is a buildup of deposits or residues from the measured chemicals it
may be necessary to clean
or flush the unit. This should be done by flowing
clean, particle free water through the unit at a flow rate, pressure and
temperature within the specifications of the unit. If necessary, flow may be
reversed to assist flushing.
Under no circumstances should gas or air be flowed through the unit. This
will cause severe damage.
3. Returning Units for Repair or Recalibration
To return units for repair or recalibration please contact Dwyer Customer
Service. A Return Material Authorization (RMA) Number will then be issued
to enable the unit to be returned. Please note that no returns will be
accepted unless the RMA number is clearly indicated on the outside of all
packages.
Once the unit has been received it will be evaluated and the cost of any
repairs / recalibration determined. Once agreement has been received to
pay for all the necessary work the unit will be processed and returned. No
charges will be made for Warranty Repairs.
Dwyer Customer Service may be contacted as follows:
Mailing address: Dwyer Instruments Inc.
P.O. Box 373, 102 Indiana Hwy. 212
Michigan City, IN 46361
U.S.A.
Phone: U.S.A. [phone] or [phone]
Fax: U.S.A. [phone]
Email: [email protected]
Website: www.dwyer-inst.com
www.calcert.com [e-mail]1.800.544.2843 0
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