Laboratory 3: CALIBRATION EXPERIMENTS

Laboratory 3: CALIBRATION EXPERIMENTS
Grading Rubric – ME487 – Calibration Laboratories 3 – 4 – 5
Total /100
Pre-laboratory Exercises (10 pts)
The Data Sheet and LabVIEW VI were submitted on time. The VI performs the specified
function and the Data Sheet is complete.
Abstract (20 pts)
Content
/5 The introductory sentence must be a specific and yet concise statement on what was
done. For example: “The PX236 pressure transducer number 2 was calibrated over the
pressure range 0–60 psig with a Bourdon tube pressure gage standard and over the
pressure range 0–100 psig with a deadweight tester standard.
/9 Statements on the most important findings. For examples include correct expressions of
the calibration curves (including units), influence of the excitation voltage on output reading
if applicable, values of the linearity and hysteresis errors if applicable, comparison of the
instrument errors or the static sensitivity to that reported by the manufacturer, and
comparisons of the results from the two setups of the thermocouple calibration.
Style
/6 All students should have NO grammar or spelling mistakes (no exceptions). Subtract one
point per misspelled word and grammar mistake. Sentences should be accurate (say what
they mean). Overall the abstract should be one paragraph revolving around the theme of
“what was done and what was learned.” Emphasis for these calibrations is on the accuracy
of the technical statements and on word choice.
Results (10 pts)
Look for the following:
Figures are on the same 8.5” X 11” piece of paper in the report. Use 2 or more pages if
necessary.
Filled black and white circles are used to display the data points on the graphs.
Calibration curves are displayed as solid black lines on the graphs.
The graphs are captioned and labeled as Figure 1, Figure 2, etc.
The captions are positioned below the graphs on the page.
A legend is present and positioned on the graphs.
The captions are descriptive, yet concise. They contain no more than two sentences.
Conclusions: Discussion (25 pts)
Text will be graded on the following: Clearly include 3 to 5 main findings!
Content
/20 ptsFor each main finding, start with a topic sentences that should revolve around the
conclusion justified based on data in figures or tables or contained in the worksheet and/or
based on observation. Conclusions should be some combination of the following: the
calibration curve equations, the instrument errors, the impact of the excitation voltage on
the transducer output, and commentary on the concomitancy of the results using the using
the deadweight tester and manufacturer’s data if available.
Style
/5 pts
The topic sentences in each paragraph should be fully supported by evidence and or
argumentation. Besides checking for accuracy of sentences and word choice, statements
should logically support the topic sentence of the paragraph. The sentences should say
what the author really intends. The style grade is based on the content of the paragraph
and less on the readability. The focus is on developing a strong topic sentence and logical
proof of the point in that sentence.
Worksheet (20 pts)
You should include a proper regression analysis. You should have properly established
the linearity and hysteresis errors. You should have established the input and output
spans for the calibration. You should have identified the transducer static sensitivity. It
should be easy to see which data were used for establishing errors and which data were
used in the confirmation calculation section.
Confirmation Calculations (5 pts)
You should have confirmation calculations for the linearity and hysteresis (if applicable)
errors based on the calibration stations. The work should be neat and it should be easy to
cross reference a calculation with the worksheet. If not, you will lose points either here or
in worksheet, but not both.
Data Sheet (5 pts)
The datasheet must be complete: lab partners listed at top, location of experiment,
equipment list with inventory or serial numbers where possible, date, raw data only, and
important observations.
Formatting (5 pts)
See the “Guidelines for Laboratory Reports in ME 487” in the PowerPoint slides
for proper formatting. To the extent possible (with the exception of the Results), Format
points are deducted here. Each section of the report should start on a new page. Use
only the front page of the paper. Every team member MUST sign before submitting the
printed version of the report.I. Temperature Measurements: Calibration of a Thermocouple
(TC), an Electrical Temperature Sensor
Introduction
The purpose of this laboratory is to teach you how to construct thermocouple circuits using a
thermocouple welder and calibrate a T-Type thermocouple circuit. You will:
 Experimentally verify thermocouple circuit theory by constructing and testing a T – type
thermocouple circuit to determine the measured temperature from the measured voltage.
 Implement two thermocouple setups, one with the TC you constructed, and another with a
provided TC of the same Type. The setup using the constructed TC runs through the Omega
TRCIII-A ICE POINT Calibration Reference Chamber used as the reference junction and the
setup using the provided TC will have the “un-welded” end of the TC exposed to the room
temperature as reference junction, and then connected to a voltage – measuring device.
You will then compare the measured voltage of your constructed TC to the calculated
voltage of the provided TC using a reference table for the T – Type TC.
Objectives
1. Fabricate a T-Type (Copper-Constantan) thermocouple circuit using a thermocouple welder.
2. Calibrate a T-Type thermocouple circuit over the temperature range 80 °F to 250 °F, with
increment of about 15 °F.
a. Verify the voltage produced by the fabricated TC at the boiling point of water, 212 °F
(100 °C)
3. Use linear regression to establish the correlation between temperature and open-circuit
emf.
4. Use an Omega RS – 232 Data Logger Thermometer as the standard.
5. Learn how to use an Omega CL 950 HOT POINT calibration Cell as a standard to establish a
measuring junction for the calibration of temperature – measuring instruments.
6. Establish the systematic uncertainty of the thermocouple based on the calibration data and
compare it with the expected systematic uncertainty if one were to use the NIST calibration.
7. Test thermocouple circuit theory by measuring the emf of the TC circuit and use the
provided table to verify the measured temperature.
Equipment
o DCC Corporation HOTSPOT thermocouple arc welder
o T – Type Copper-Constantan insulated TC wire pairs
o Dell personal computer with NI cDAQ – 9174 data acquisition (DAQ) hardware with NI USB,
A NI 9219, 4 – Channel +/- 10 V, 16 –Bit Analog Voltage Output Module with integrated
signal conditioning.o A 4 – channel handheld Omega RS – 232 Data Logger Thermometer – HH 147, with ±0.1 %
reading + 0.7 °C (1.4 °F) accuracy.
o A SIGHTECH Eye Protection Goggles
o An Omega TRCIII-A ICE POINT Calibration Reference Chamber
o An Omega CL 950 HOT POINT Cell calibration Cell
o An Omega T – type 2 TC – in – 1 Thermocouple probe
o Pliers, wire cutters, wire strippers
o 2 Keithley 2110 5 ½ Digit Multimeter
o A Beaker with Boiling water
o A Hot Plate
Background
Thermocouple circuits are the most common approach for measuring temperature. They are
inexpensive, can be made small in size to provide fast response times, and, with special care, can be
accurate with an instrument uncertainty as low as ±0.1 °C (95%). In typical applications, however,
the instrument uncertainty of thermocouple-based temperature measuring systems is ±2 °C (95%)
or greater.
Figure 1: The Setup for the Thermocouple Calibration ExperimentFigure 2: The NI cDAQ – 9174 data acquisition (DAQ) hardware with NI USB – 9213, 16 – Channel
TC input Module and A NI 9219, 4 – Channel +/- 10 V, 16 –Bit Analog Voltage Output Module with
integrated signal conditionings available in the lab
A thermocouple consists of two dissimilar metals mechanically joined at one end. The union of the
metal pieces is called the junction of the thermocouple. The junction may be created by welding,
soldering, twisting the wires around one another, or any method that provides a good electrical
contact between the metals. In this laboratory, you will create a thermocouple junction using a
HOTSPOT TC arc welder.
Figure 3: The Omega TRCIII-A ICE POINT Calibration Reference Chamber and Omega CL 950 HOT
POINT calibration Cell available in the labThermocouple Calibration Experiment Procedure
There is one station set up in the laboratory for the thermocouple calibration experiment. Each
group will work at the station until the part of the laboratory where your group will verify
thermocouple circuit theory.
Part 1: Fabrication of a Thermocouple Circuit
Figure 4: The DCC Corporation HOTSPOT thermocouple arc welder with required tools and
protective goggles
1. Your instructor or TA will demonstrate how to use the arc welder to construct a
thermocouple circuit from the copper-constantan wire provided.
2. Your laboratory group will construct a TC circuit to be calibrated. Three members of the
group should make one attempt at preparing and welding TC wires and select the best
thermocouple circuit fabricated for calibration.
3. Prepare the wires to construct the TCs using wire strippers, wire cutters, and pliers provided
at your laboratory station.
Figure 5: The Omega RS – 232 Data Logger ThermometerFigure 6: The Omega provided Thermocouple probes
Part 2: Calibration of a T-Type Thermocouple Circuit
As pre – lab, begin to create the LabVIEW program that you will use to read the thermocouple
circuit voltage:
1. Create a LabVIEW program that will read, display, and, when desired, store in a text file the
T-Type thermocouple circuit emf (voltage). Recall that the T.C. voltage will be in the millivolt
range. Set the input range of the DAQ Assistant accordingly and display the voltage with the
units of millivolts on the front panel readouts.
2. Thermocouple Calibration:
Connect your thermocouple circuit using appropriate connectors to both the Hot and Ice
point.
a. Pre-cool the Ice point reference chamber and pre-heat the hot box about a half
hour before the experiment run so they have time to reach equilibrium. Insert the T
– type TC probe into the ice point reference chamber at this time as well.
b. Secure the two un-welded wires on the other end of the constructed TC to a T –
type thermocouple connector, and connect it to the T – type blue TC connector of
the T – type TC probe connector going into the ice point chamber. Using a T – type
extension wire, connect the white U – connector of the provided TC probe to 2 iron
wires going to the multimeter.
c. Insert the welded end of the constructed thermocouple all the way into the hot box
and record the resulting voltage after the temperature of the hot box has stabilized
at 80 °F and the resulting voltage.
d. Perform step c. at 12 to 15 other temperatures in increments of 15 °F increasing the
temperature hot point cell from 80 °F to 250 °F, one of which being the boiling point
of water (212 °F).
e. Remove the thermocouple from the hot box, stick the welded end into a boiling
volume of water, and record the resulting voltage.
f. Remove the thermocouple from the boiling water and turn off the multimeter, ice
point reference chamber, hot box, and boiling water.Part 3: Verification of Thermocouple Circuit Theory
In the circuits, Thot is the temperature of the hot point cell and Tcold is the temperature of
the reference junction at ~0 °C. Once the circuit has been constructed, your group will do
the following:
a. To verify thermocouple circuit theory, create the Moffat diagram for the
thermocouple circuit configuration used during the TC calibration. You will be
turning the Moffat diagram in with your laboratory report, so work to make them
neat and work on a separate sheet of paper.
b. Measure the emf of the circuit using the data acquisition system at the station.
c. Using your Moffat diagram in tandem with the provided Table and Beasley (the
NIST calibration for a T-Type T.C.), convert the measured emf into measured
temperature.
d. Compare the measured temperature (via the thermocouple circuit) with the
temperature indicated by the hot point cell standard.
Post-laboratory Work
Report: The report on this part is a group report and will be submitted the following week. Your
report should be assembled in the following order:
(1) Cover Page
(2) Abstract
(3) Results
(4) Conclusions
(5) Worksheet
(6) Sample Calculations including uncertainty analysis
(7) Datasheet.
Results
1. A table of the calibration temperatures, all measured and calculated emfs for both the
constructed and provided TCs, including values from the LabVIEW program for the
constructed TC.
2. Provide the calibration data and the calibration curve for T-type T.C. in a figure labeled
Figure 1 and captioned accordingly. Follow the formatting rules for figure generation. Refer
to handout of the formatting of figures in ME.
3. Sketch the circuit and its Moffat diagram.
Confirmation Calculations/Uncertainty Analysis
Include confirmation calculations for your uncertainty analysis of the calibration experiment. The
analysis that allows one to convert the emf measured in the circuit into temperature. Report the
measured emf, its corresponding temperature, the temperature indicated by the hot point cell
standard, and the percent difference between the standard temperature and the measured
temperature (circle, highlight, or box these values). Your sketch and your work should be neat and
easy-to-follow. Fully develop the required equations, and then substitute values AND their units
into the equations to calculate the result. Report the results with a reasonable number of significant
digits/decimal places and include units! You do not need to conduct an uncertainty analysis for the
verification of the TC theory.II. Pressure Measurements: Calibration of a Pressure
Transducer
The purpose of this laboratory is to familiarize you with the calibration process, a typical pressure
measuring transducer, and a common standard for pressure calibration.
Objectives
 Calibrate two 4-wire PX309 pressure transducers, an absolute pressure transducer and a
gauge pressure transducer:
o Use linear regression to determine the instrument’s static sensitivity
o Estimate the instrument’s linearity and hysteresis errors
 Learn how to use the AMETEK PK II Pneumatic deadweight tester
 Compare the results of calibrating the pressure transducer using a deadweight tester
standard with the manufacturer calibrations
Equipment
 Dell personal computer with NI cDAQ – 9174 data acquisition (DAQ) hardware with NI USB –
9219, 4 – Channel, +/- 10 V, 16 –Bit Analog Voltage Output Module with integrated signal
conditioning.
 NI LabVIEW 2017 (32 bit) software
 The AMETEK PK II Pneumatic Deadweight tester
 Pneumatic tubing and fittings
 Keithley 2110 5 ½ Digit Multimeter
 Power supply
 2 OMEGADYNE PX309 Pressure Transducer
 Cables connecting the DAQ system
Background
A calibration is an experiment conducted to establish the relationship between the output of a
measurement system and a known input called the standard. In a static calibration, the input does
not vary in time. In this laboratory, the measurement system consists of two 4-wire pressure
transducers manufactured by Omega Engineering Inc., and connected to the NI cDAQ – 9174 data
acquisition (DAQ) hardware unit. One standard will be applied, a deadweight tester. This is a
common laboratory standard for calibrating pressure-measuring systems.
Picture of the calibration station based on the pneumatic deadweight tester is provided in Figure 1.
In preparation for laboratory this week, you should review your course notes on calibration,
instrument errors, and standards.The OMEGA PX309 Pressure Transducer
The PX309 pressure transducer is an instrument that converts the pressure induced displacement of
a membrane into a voltage. The membrane, which is sometimes also called the diaphragm, is the
sensing element of the instrument. A strain gauge attached to the surface of the membrane serves
the role of the transducer element. The output voltage of the strain gauge circuit is proportional to
the applied pressure. Recall what you learned about strain gauges and the circuits required to
utilize them. The red and black wires of the PX309 – 100G5V pressure transducer are used to apply
the excitation voltage to the transducer circuit and the remaining white and green wires are used to
measure the output voltage. See Figure 2 for reference. The manufacturer specifications of the
PX309 pressure transducer are provided in Figure 3. The full scale range of the PX309 – 100G5V
transducer (not listed in Fig. 3) is 100 psi. DO NOT APPLY A PRESSURE GREATER THAN 100 PSI TO
THE TRANSDUCER!
Figure 1: Setup for the Calibration of the two pressure transducers
The excitation voltage of 10 V is delivered to the pressure transducer using a DC power supply. A
picture of the front of the power supply configured for providing the excitation voltage to the
transducer is provided in Figure 1.
When the power supply is switched on, you will adjust the “Voltage” knob to establish a supply
voltage of 10 V. The analog voltage meter on the front panel serves as a guide for setting the supply
voltage, but you should always check the voltage generated by a power supply with a multimeter.
NEVER CONNECT A POWER SUPPLY TO A TRANSDUCER BEFORE CHECKING THE OUTPUT VOLTAGE!Figure 2: The two pressure transducers, absolute and gauge types
Figure 3: PX309 – 100G5V Pressure transducers Manufacturer SpecificationsThe Deadweight Tester
A deadweight tester makes use of the fundamental definition of pressure as a force per unit area
and the principle of mechanical equilibrium to create a known pressure within a sealed chamber.
Deadweight testers come in three variations depending on their working fluids: gas-gas, gas-oil, and
oil-oil.
The first fluid is the fluid that comes into contact with the pressure sensor and the second fluid is
the fluid to which pressure is applied. In this laboratory, we will use a pneumatic deadweight tester.
The gas-oil deadweight tester consists of an internal chamber filled with oil, a piston-cylinder, and
vertically oriented reference pressure port to which the pressure sensor is connected (Figure 4). The
weight of the piston plus the additional weight of known masses loaded on top of the piston apply a
force that acts over the equivalent area of the piston to generate pressure. At mechanical
equilibrium, the externally applied pressure balances the oil chamber pressure and the chamber
pressure can be calculated from:
= / + Σ Error Corrections
For most calibrations, the error corrections can be ignored because their contribution to the
chamber pressure is small, on the order of 0.1%. However, when error corrections are included, the
deadweight tester instrument uncertainty can be as low as 0.01% of the pressure!
For convenience, our deadweight tester is supplied with weights calibrated to create known
pressures when applied to the piston-cylinder. Table 1 provides a list of the weights available. These
weights are shown at the bottom of Figure 6. The pressure created by the weight of the piston is
also known and written on the top of the piston platform for easy reference. This is the lowest
pressure that can be generated by the deadweight tester. To calculate the pressure created, add
the piston pressure to the pressure values associated with each weight. For example, if you add two
4 kPA weights to the piston platform, the pressure created will be 2 kPA + 4 kPA + 4 kPA = 10 kPA
when mechanical equilibrium is established. As part of your pre-laboratory exercises, you will
determine the various combinations of weights required to create 12 equally spaced points over
the full-scale input range of the PX236 pressure transducer.Figure 5: PX309 – 100G5V Pressure transducers with shown wires
Figure 6: Standard Masses used the pneumatic Deadweight Tester available in the lab
Standard Weight Number of Weights
2 kPA 2
4 kPA 1
10 kPA 2
20 kPA 1
50 kPA 3
Base
1 kPA 1
2 kPA 1
Table 1: Standard Weights Provided with the Deadweight Tester
AMETEK PK II Pneumatic deadweight tester
Figure 7: The PK II Pneumatic Deadweight Tester available in the labThe PK II floating ball type pneumatic dead weight tester is engineered to offer user-friendly,
safe operation. The easy-to-use primary standard provides reliable and accurate pressure
measurement in the field, or in a lab.
• Accuracy to 0.015% of reading
• Ranges to 30 psi
• Available in psi, g/cm², bar, mbar, kPa, inH₂O, cmH₂O, and mmHg
• Small incremental weight sets provide fractional output pressure
Featuring a self-regulating design, that allows automatic stabilization of weights, eliminating
the need to adjust input pressure.
• Rugged ceramic measuring ball
• Overhung weight carrier reduces side thrust and friction
• Quick-leveling system for field use
• Optional Tripod
Local gravity and standard gravity versions available.
Figure 7: The Keithley 2110 5 ½ Digit Multimeter and the Power Supply available in the labPK II Deadweight Tester Operation Steps
The pneumatic deadweight tester is operated to calibrate a pressure transducer by following these
steps:
1. Ensure that the pressure sensor is tightly connected to the reference port. This step will be
completed for you prior to the start of the laboratory. You will then make sure to tightly
connect the second pressure transducer when starting its calibration.
2. Also connect the multimeter, the power supply, and the NI cDAQ – 9174 data acquisition
(DAQ) hardware
3. Slip the weight carrier over the ceramic ball and nozzle assembly
4. Admit the supply pressure to the tester by turning on the valve marked “INLET”
a. Never apply or connect a pressure source greater than 100 PSIG to the PK II
Deadweight tester
b. Applying high pressure may result in personal injury and damage to the tester.
5. Record the resulting voltage reading with no applied pressure.
6. Open the tester “OUTLET” valve and CALIBRATE the instrument
a. Record the outputs of the pressure sensor on your Data Sheet and remember to
save your Data Sheet often in case of a power outage.
7. Incrementally add weights to applied pressure until no more weights can be applied. Record
the resulting voltages of each increase.
a. Exercise caution when handling the weights.
b. Handle only one weight at a time to avoid damaging the weights
c. Weight may be given a slow rotary motion to ensure that the weights rotate without
abrupt stopping and that the mechanical equilibrium is established.
d. DO NOT SPIN the weights unless the ceramic ball is floating.
8. Incrementally decrease the applied pressure until there is no more pressure being applied.
Record the resulting voltages of each decrease.
9. Once the calibration is complete, if a zero PSIG output is desired, the downstream pressure
may be vented by turning the outlet vale to the “VENT” position. The tester internal
pressure will not be vented.
10. Disconnect the absolute pressure transducer.
11. Repeat steps 7 through 10 using the second pressure transducer.
12. Turn off all equipmentYou should be familiar with the operation of the deadweight tester before
coming to laboratory.
Study the Influence of the Excitation Voltage on the Transducer
Output Voltage
After you have collected the calibration data, load the PX309 – 100G5V Gage transducer to a
pressure of 100 kPA. Hold this pressure and lower the excitation voltage to 8 V and 6 V,
respectively, recording the transducer output voltage once it has stabilized. You will draw some
conclusions about your observation.
Post Laboratory Work
Prepare and submit a report for this part of the calibration experiments. As a reminder, this is a
group report and should include all the calibration experiments clearly separated. Therefore, all
written portions of the report must be a group effort working together as a team, as well as to
complete calculations by hand and in the worksheet and to prepare figures.
Report
Your instructor is expecting your report to be assembled in the following order:
(1) Cover Page (same for all three calibrations)
(2) Abstract
(3) Results
(4) Conclusions
(5) Worksheet
(6) Sample Calculations including uncertainty analysis
(7) Datasheet.
Calculations
1) Determine the correlation between the input and output values of the two PX309
transducers that you calibrated in the laboratory. Use a linear least-squares regression.
Clearly label the static sensitivities and zero offsets of the transducers in your worksheet,
and included proper units.
2) Determine the linearity and hysteresis errors in the transducer calibrated using the
pneumatic deadweight tester. Be sure to clearly indicate in your worksheet which data
points are being used for the error estimate. Complete the calculation in your worksheet
and also complete confirmation calculations by hand.
3) Determine the upper and lower range values for the input and output.
4) Determine and report the resolution of the input pressure.Figures
1) Plot the transducer output voltage versus the pressure for the deadweight tester in Excel or
MATLAB for the two pressure transducers. Put the plots onto a – 8.5” X 11” page in your
report and use open circles to display the data points.
2) Add the best-fit lines of the data determined from the linear regressions to the plots. The
lines should be solid and black with a thickness no less than 1 pt.
3) Be sure to clearly label the axes, data, and the best-fit line on your graphs. Also, the graphs
should have appropriate captions with the labels Figure 1, Figure 2, and so on.
Conclusions
The following questions should guide your thoughts on writing up the report’s abstract and
conclusions: What do the results of your calibration specifically tell you about the operation of your
transducer? How does your measure of the transducer’s sensitivity and linearity error compare with
the values supplied by the manufacturer? Does the transducer’s excitation voltage influence its
output? Are there significant differences between the static sensitivity of the transducers as
determined via the calibrations with the deadweight tester for both transducers? What about the
zero offsets?III. Flow Measurements: Turbine Flow Meter Calibration
The purpose of this laboratory is to calibrate a turbine flowmeter for water flow using the F1-10
HYDRAULICS BENCH. You will thus be exposed to a high-end device for measuring water flow.
Objectives
 Calibrate a turbine flow meter:
o Use linear regression to develop the correlation between the rotational speed of the
turbine and the water volume flow rate
o Establish the calibration bias error of the turbine flow meter
o Implement the catch-and-weigh technique for liquid flows to determine the mass flow
rate.
Equipment
 F1-10 HYDRAULICS bench with flow tube and measurable basin
 Omega FTB – 1412 turbine flowmeter
 Dell personal computer with NI cDAQ – 9174 data acquisition (DAQ) hardware with NI USB –
9219, 4 – Channel, +/- 10 V, 16 –Bit Analog Voltage Output Module with integrated signal
conditioning.
 NI LabVIEW 2017 Software
 Digital stopwatch
 Garden hoses
 Oscilloscope
 1000 mL Beaker
 Mass scale
Background
Paddlewheel Flow Meters
Paddlewheel flowmeters, and their more accurate cousin the turbine flowmeter, make use of
angular momentum principles to meter liquid flow rate. In a typical design, a rotor is encased within
a bored housing through which the fluid to be metered is passed. The housing contains flanges or
threads for direct insertion into a pipeline. The exchange of momentum within the flow turns the
rotor at a rotational speed that is proportional to the flow rate. Rotor rotation can be measured in a
number of ways. For example, the paddlewheel meter that you will calibrate in laboratory this week
features a magnetic pickup coil that senses the passage of the rotor blades, producing a pulse train
AC voltage signal with a frequency that is directly related to rotational speed.Turbine meters offer a low-pressure drop and very good accuracy. A typical instrument’s systematic
uncertainty in flow rate is ~0.25% (95%). Additionally, the measurements are exceptionally
repeatable making these meters good candidates for local flow rate standards. However, turbine
rotational speed is sensitive to temperature changes, which affect the fluid viscosity and density,
and therefore its sensitivity. Some compensation for viscosity variations can be made electronically.
The turbine meter is also susceptible to installation errors caused by pipe flow swirl, and a careful
selection of installation position must be made. Paddlewheel meters are less accurate than turbine
meters (typically 1% (95%) of the FSO) but also tend to be more robust when used to meter dirty
liquids containing particulates. An engineering drawing of the paddlewheel meter that you will
calibrate in laboratory this week is shown in Fig. 6.
F1-10 Hydraulics Bench
 Mobile, floor standing service unit for fluid mechanics apparatus
 Base constructed from robust, corrosion resistant plastic molding
 Top constructed from glass reinforced plastic
 Sump tank capacity 250 liters
 Volumetric flow measurement via remote sight gauge
 Stepped tank for low and high flowrates. Capacities 0-6 and 0-40 liters
 Open channel in bench top with quick release outlet fitting
 Self-priming centrifugal circulating pump provides water at 21m head at no flow, and a maximum
flow of 60 liters per minute
Figure 1: F1 – 10 Hydraulics BenchExperimental Setup for Calibration of the Turbine Flowmeter
You will calibrate the turbine flowmeter using the F1-10 hydraulics bench shown in Fig. ?. The
strategy is to flow water through the turbine flowmeter and into a holding stepped tank on the F –
10 hydraulic bench. The bench has a sight glass scale that measures the volume of the water
collected in the stepped tank in Liters. A stopwatch is used to measure the time required to collect
a given amount of water at a specific flow rate. The temperature of the water is measured so that
its density can be determined. The mass flow rate is then calculated from the time required to
collect the given volume of water and the water density. The water temperature is measured with a
precision thermometer. The systematic uncertainty of the thermometer is ±0.5 °F.
Figure 2: Volume measurement sight glass and the oscilloscope to measure the output frequencyFigure 3: The Omega FTB – 1412 turbine flowmeter
Figure 4: The Omega FTB – 1412 turbine flowmeter connected to the Oscilloscope to measure the
meter frequency output.
Figure 5: Cole Parmer mass scaleCalibration of a Paddlewheel Meter
Create a LabVIEW program to acquire the pulsed AC voltage output of the turbine flowmeter via the
NI cDAQ – 9174 data acquisition (DAQ) hardware. You will determine the frequency of the pulses via
the fast Fourier transform (FFT) of the pulsed output.
Use what you have learned in the previous laboratory and other course laboratories if necessary.
Include in your program a FFT of the turbine flowmeter output. The frequency of the pulsed output
is the fundamental frequency of the magnitude portion of the FFT of the turbine meter output.
Apply a Hanning window.
For the actual calibration, you will take an equally spaced set of data for the turbine flowmeter. Do
a quick pretest to establish the range for the test. Start at the maximum flow for the system. Find
approximately the minimum flow for which the turbine flowmeter works. Use the volume scale on
the F – 10 hydraulic bench and a stopwatch as the standard to measure the volume and time for a
given amount of water to flow. Remember to measure the temperature of the water so its density
can be determined. Convert the volume flow rate to gallons per minute (gpm).
Flowmeter Calibration Procedure:
1. Read and record the atmospheric pressure and the water temperature.
2. Connect the flowmeter to the provided oscilloscope and the flow tube of the water bench.
3. Fill the basin to the zero point of the 0 L to 40 L scale and stop the flow.
4. Open the gate valve corresponding to your minimum flow rate. Read and record the initial
water level in the tank using the sight glass. Read the final level, 40 L, and the elapsed time
using a stopwatch. Note that the longer you wait, the more accurate your measurement will
be. Wait at least 1 minute and 30 seconds between the start and stop time to ensure good
results. Start the stopwatch and the flow simultaneously.
5. Record the time from the stopwatch and the frequency from the oscilloscope every 40
Liters.
6. By adjusting the gate valve, repeat steps 4 and 5 for higher volume flowrates, taking at least
10 measurements between the minimum and the maximum flowrates, turning off the water
flow and emptying the basin each time.
7. Measure the mass of a 1000 mL beaker on a mass scale and tare it.
8. Using a stopwatch, record the time it takes to fill the beaker from empty to a readable point
on the beaker. Record the final volume that the beaker was filled to and the frequency of
the flowmeter from the oscilloscope.
9. Read Record the mass of the water collected in the beaker during step 8 using the mass
scale.Results
On a single 8.5” X 11” piece of paper:
1) Report the calibration curve as they would be used by an engineer in the field for the
turbine flowmeter. Include with the calibration curve the associated instrument uncertainty
based on the calibration. Do not forget units.
2) Below the equation for the calibration curve, provide a figure with the turbine flowmeter
calibration data. Follow the figure formatting guidelines. Label the figure as Figure … and
write an appropriate caption.
3) Label the top of the page: “Results”.
Confirmation Calculations/Uncertainty Analysis
Include confirmation calculations for the volume flow rate from the F – 10 hydraulic bench and its
conversion to the units of gpm, and for all uncertainty calculations.
Report
Your instructor is expecting your report to be assembled in the final report in the following order:
(1) Cover Page (same for all three calibrations)
(2) Abstract
(3) Results
(4) Conclusions
(5) Worksheet
(6) Sample Calculations including uncertainty analysis
(7) Datasheet.
SUMMARY OF THE
Calibration of Pressure Transducers (with deadweight tester), Calibration of
Turbine Flow Meter & Calibration of Thermocouples
Note: One pressure transducer should have a range of xx-yy PSIG and the other one should have cc-dd
PSIA. That is, do not calibrate two of the same “type”, i.e., both having PSIG or both having PSIA; you
should calibrate one of each.
Pressure Transducer Calibrations with the Dead Weight Tester
1. Calibrate the given pressure transducers (NB: follow all directions on the deadweight tester and
treat it with care! Do not over-pressurize the transducer!)
2. Collect 10 or so points evenly spaced over the operating range of the pressure transducer when
going from the unloaded state to the maximum applied pressure.3. Repeat step 2 but unload the pressure transducer.
4. Use Labview to record your data into the Datasheet.
5. Use Matlab or Excel to post-process your data into the Worksheet.
6. Include an uncertainty analysis in your Worksheet.
7. Use Matlab or Excel to regress your data into your Worksheet.
8. How does your data compare to the manufacturer’s data?
9. Do you see any hysteresis effects?
10. What is the functional form of the output to the input? E.g., is it linear, quadratic, power of ½,
etc.?
11. Draw other conclusions based on what you were asked to do and your results section
12. Your write up should include: (1) Cover Page for all 3 calibrations, (2) Abstract, (3) results (4)
Conclusions, (5) Worksheet, (6) Sample Calculations including uncertainty analysis, (7)
Datasheet.
Turbine Flow Meter calibration
1. How to setup up your calibration loop? Think about how to do it! We will discuss in class.
2. Calibrate the turbine flow meter.
3. Calibrate frequency output to liquid output: (1) volume per time and (2) mass per time.
4. Use Labview to record your data.
5. Use Matlab to post-process your data.
6. Include an uncertainty analysis.
7. Use Matlab to regress your data.
8. How does your data compare to the manufacturer’s data?
9. What is the functional form of the output to the input? E.g., is it linear, quadratic, power of ½,
etc.?
10. Draw other conclusions based on what you were asked to do and your results section
11. Your write up should describe briefly: (1) Cover Page, (2) Abstract, (3) results (4) Conclusions, (5)
Worksheet, (6) Sample Calculations including uncertainty analysis, (7) Datasheet.
Thermocouple Calibration
1. Create (weld) one thermocouple.
2. Pick a manufactured thermocouple made of the same wire type as the one you created.
3. Calibrate both thermocouples using the hot point and ice point.
4. Use Labview to record your data.
5. Use Matlab to post-process your data.
6. Describe qualitatively the sources of error.
7. Was there a difference between the manufactured and lab-made thermocouple? Why or why
not?
8. Draw other conclusions based on what you were asked to do and your results section9. Your write up should describe briefly: (1) Cover Page, (2) Abstract, (3) results (4) Conclusions, (5)
Worksheet, (6) Sample Calculations including uncertainty analysis, (7) Datasheet.
THINGS TO THINK ABOUT WHEN PREPARING CALIBRATION WRITE- UP
Before writing the calibration reports, ask yourself a bunch of questions:
What is important to tell me (the reader)?
Jump to the end for a second and think about it? Isn’t what you ultimately want to say to me is that you
have calibrated such and such a transducer over such and such range and operating conditions with
such and such uncertainty?
So, then what is important to me (the reader)? Some things (not in order):
1. What did you calibrate?
a. Here you need to be specific:
i. What instrument did you calibrate? It was a very specific one with known manufacturer,
model number, serial number, stated operating ranges, …
ii. What is the working principle of the instrument?
b. What did you actually calibrate, that is, what was (were) the input(s) and what was (were) the
output(s)?
2. How did you calibrate the instrument?
a. What instruments did you use to calibrate? Again, be specific with models, uncertainties, etc.
3. Were the operating conditions important? If so, what were they?
4. What working fluid was used for calibration?
5. You should provide in tabular form (with appropriate title, column headings, units, …) the calibration
results.
6. You should estimate your expanded uncertainties.
7. You should provide a calibration curve (again appropriate title, labeled axes with units, …). You can
then compare your results to the manufacturer’s calibration (you should have gotten the calibration
data for your specific instrument), with some critical comments.
A few general comments from previous years’ write-ups:
1. You did not calibrate a deadweight tester. Your deadweight tester served as a “standard”. You
calibrated a pressure transducer.
2. Do not use the term “theoretical” when you really mean “manufacturer’s calibration data”
3. Perform an expanded uncertainty analysis with coverage factor when possible.
4. Ask yourself: Does my data make any sense? Is it any “good”? How do you know?
Provide some discussion/conclusions. For example, why do/don’t your results agree with the
manufacturer’s data?