Learn how to properly mount and calibrate strain gages. When making strain measurements it is important to perform a shunt calibration both before and after the actual measurements are acquired. The shunt calibration module works for any of epsilons strain gaged extensometers and with nearly any electronics. The 9155 system also calibrates piezoresistive mems, capacitive, and velocity sensors via available options. Calibration of the monitor must be considered in conjunction with the color management system used by the design software and by the computer itself. Shunt calibration helps you accurately set your control system. Here are stepbystep instructions for shunt calibration of a strain gauge load cell. The selection of a calibration system is often made on price, but should also consider some other factors, as any system is only as effective as its operator. Subtract no load zero value from shunt applied value. Entering information into the front panel fields running the. Clicking run will measure the battery testing system response to the calibration. Starting the calibration software running the voltage vi 2 3. Shunt calibration uncertainty budgets consist of type b components, which are under the labs control, combined with type a components unique to the unit under test at the time of test. With shunt calibration, onsite electrical calibration can be performed with almost all types of electronics and controllers.
The ni 9237 shunt calibration circuitry consists of a precision resistor and a software controlled switch. See shunt calibration gain adjustment for more information. Shunt calibration to properly calibrate any shunt the same procedures must be followed regardless of the type or brand of software being used. The calibrated standard shunt may have an uncertainty of 0. Ensure that the shunt calibration terminals are connected properly and that the shunt resistance and shunt element location settings match how the hardware is wired. For verification purposes, the value for every unit is laser etched on the housing of models 422423. System calibration is accomplished through the use of software. Sep 07, 2017 use shunt calibration to ensure that your instrumentation is scaled to correct engineering units and is within accuracy expectations. As shown in the photos to the right, the module is a simple plug in device containing the shunt resistor.
The epsilon shunt calibration system offers an easy method to calibrate an extensometer as well as signal conditioning electronics, without using a mechanical calibrator. These versatile automated calibration systems reduce calibration time and cost, permitting efficient in. The 9237 has an internal shunt resistor of 100 kohm. To perform a shunt calibration using the 701271 strain gage module and the. Apg shunt calibration at apg, our hammer union 1502 and 22022002 pressure transmitters are the only sensors we build with shunt calibration. The voltech at series calibration system consists of a calibration fixture, a pc not supplied running the voltech calibration software, a printer and a precision digital voltmeter not supplied. Strainsmart is a readytouse, windowsbased software package for acquiring, reducing, presenting, and storing measurement data from strain gages, straingagebased transducers, thermocouples, temperature sensors, lvdts, potentiometers, piezoelectric sensors, and other commonly used transducers. The epsilon shunt calibration system is an option for any straingauged.
That output can then be measured precisely to calibrate your control system s. This is the shunt calibration value in mv multiply by to express in uv. With available options the system allows nist traceable calibrations from 0. The 3000cs provides a precision set of current shunts for current ranges from 10ma to 10a, providing additional ranges for multimeters that either lack sufficient accuracy at required currents, or lack the required current ranges entirely. Feb 26, 2020 typically, the shunt resistor is connected across r3, however it is possible to use any of the wheatstone bridge arms as long as it is specified as an input for the shunt calibration vi. The resulting bridge output is useful for calibrating or scaling instrumentation. Use shunt calibration to ensure that your instrumentation is scaled to correct engineering units and is within accuracy expectations. This instrument is capable of performing shunt calibration on single, dual, or triple bridge load cells simultaneously and in a fully automated manner. Connecting strain gauges and shunt resistors to the ni9237.
In the second scenario, shunt cal can be used for troubleshooting your transducer. Shunt calibration is a technique for simulating strain in a piezoresistive strain gage wheatstone bridge circuit by shunting one leg of the bridge. The ni 9237 shunt calibration circuitry consists of a precision resistor and a softwarecontrolled switch. You can use max to quickly verify the accuracy of your measurement system setup. Shunt calibration features in high accuracy transmitters. Checking hbm torque flanges using the shunt signal and the. Its not a complete calibration, since no actual pressure is applied when conducting a shunt calibration, but it does reduce the errors associated with the electrical characteristics of the.
Mts series 793 tuning and calibration university of south. This is the normalized shunt calibration value in uv per volt. If you are calibrating current and the circuit uses a shunt, you need to select shunt choice from the digital multimeter field, and input an accurate value for resistance. In this micromeasurements inotes video, darryl explains. To ensurefield accuracy, the prs801cc calibration shunt is used to confirm and adjust the accuracy of its 0. It can remove errors from your measurements and therefore reduce the measurement uncertainty of your instrumentation system.
Shunt calibration is a convenient way of calibrating a wheatstone bridge strain gauge circuit which is a common technology used in pressure transducers. Loading the acdc difference program running the voltage vi 1 2. The magic of wiser is the unique design of the data acquisition system coupled with the high fidelity, realtime communications system, which delivers fully processed data ready for viewing directly from the source. Operation and reference manual for the nist acdc calibration. These versatile automated calibration systems reduce calibration time and cost, permitting efficient inhouse transducer calibration. Shunt calibration zero balance and function test with shunt resistor. Wtviewere application software wtviewerfreeplus for wt300wt300e series. In the following procedures, the directions are based on eatons dctools or its web based version for the sc200 system controller. The comparison calibration method uses a calibrated standard shunt in series with a shunt under test. This value is the end result of the shunt calibration and is used to scale strain measurements on this channel. Shunt calibration gain adjustment shunt calibration is the procedure to verify the output of a strain gage measurement system relative to some predetermined mechanical input or strain. This paper explains how fast and precise calibration procedures can be carried out automatically by means of simple shunt resistor switching technique. Calibration system an overview sciencedirect topics.
System requirements system requirements 1 running the voltage system vi 1. How do i perform a shunt calibration with the scopecorder strain. To complete the shunt calibration, the signal conditioning electronics or software are adjusted so that the extensometers readout matches the shunted reading. Apr 22, 2019 when making strain measurements it is important to perform a shunt calibration both before and after the actual measurements are acquired. The system allows nist traceable calibration in 5 hz to 10 khz bandwidth. This nisttraceable wheatstone bridge calibrator offers. The software will then automatically recalculate the values, according to the given. The shunt calibration data provides a means for the user in the field to verify system scaling, and as many instruments can be scaled using this data it provides a means to temporarily restore a calibration in the field.
Shunt calibration involves simulating the input of strain by changing the resistance of an arm in the bridge by some known amount. Errors are introduced from the cabling between your instrumentation components, wiring from you sensor to your instrumentation frontend, and inaccuracies. Calibration of such big systems can be a tedious task. The current to be measured is connected to the shunt via binding posts. Connect the transducer to an appropriate strain gauge signal conditioner and allow adequate time for the system to stabilize. Alternatively, this method can also be used to adjust the output signal of the wheatstone bridge to 0 mv. By the parallel connection of a resistor rp to a strain gauge, a defined detuning of the measuring bridge can be brought about. The system is turnkey, fully automated, step sine excited and based on fft. Tovey engineering transfer standard force calibration systems are available in capacities ranging from 20 lbf to 1 million lbf. Shunt calibration enables performing onsite electrical calibration with nearly all types of controllers and electronics. Software for stress analysis testing system 7000 10 to 2048 measurements per second per sensor selectable digital filtering of measurement signals time and frequency domain analysis self calibration with internal calibration reference system 8000 eight softwareselectable input channels up to 16 scanners can be used. Ac current shunt electrical standards fluke calibration. Either a shunt resistor is applied to the transducer circuit, or voltage is applied to an ancillary circuit designed to generate a fullscale output. Setting shunt calibration in scan mode for compactrio.
It is particularly important to distinguish between two modes of shunt calibration which are referred to in this tech note, somewhat arbitrarily, as instrument scaling and instrument verification. The software is capable of shunting any arm of the bridges using any of the eight shunt resistors. An automated shunt cal module features four separate shunt calibration values. Any number of these resistor values can be switched into the circuit in sequence or used individually. If used to calibrate metering shunts, with accuracies to 0. Shunt calibration of strain gage instrumentation shuntcalibration relationships are sometimes required for different sets of circumstances. Vpg is an internationally recognized designer, manufacturer and marketer of systems and components based on its resistive foil technology, sensors, and sensorbased systems. Use system calibration to ensure accurate measurements. The wiser 4000 enables positive and negative shunt calibration with two independent shunt calibration legs using 100 k. For calibrating voltech at series testers such as the ati and at3600, but not the discontinued products at and at3500. The a40b dc and ac precision current shunt set consists of 14 lowinductance coaxial current shunts, adapters and connectors, and a rugged transitstorage case. Refer to the software help for information about enabling the shunt calibration switch for the ni 9237. Any number of these resistor values can be switched into the circuit in sequence.
Shunt calibration involves simulating the input of strain by changing the resistance of an arm in the bridge by a known amount. However, depending on the application or quality standards, i. Divide shunt calibration value by measured excitation, multiply result by. A headless scopecorder system capable of connecting multiple chassis into. Readings or outputs for a load cell and indicator or amplifier system are most commonly taken. System 7100 system 7100 data acquisition system strain gage input cards strain gage input cards accomplish bridge excitation, bridge completion, shunt calibration, and signal conditioning for eight quarter, half and fullbridges. The accelerometer calibration workstation model 9155 offers accurate backtoback comparison calibrations of icp iepe and charge mode piezoelectric accelerometers in accordance with iso 1606321. Typically, the shunt resistor is connected across r3, however it is possible to use any of the wheatstone bridge arms as long as it is specified as an input for the shunt calibration vi. Electromechanical materials test system hydromechanical materials test system vehicle. Strain gauge shunt equivalent calculations in itestsystem itm. The bridge may be internal to a discreet transducer or composed of separately applied strain gages. Designed for currents from 1 ma to 100a, the current shunts are for laboratory use in making directly measured absolute ac or dc current measurements as well as acdc current transfer. You can find the set shunt calibration scan interface vi located at. System 7100 data acquisition system this highperformance data acquisition system employs a 24bit analogto.
Advanced driver assistance systems adas testing vehicle brake test and abs. System 7100 data acquisition system this highperformance data acquisition system employs a 24bit analogtodigital converter in each sensor channel. The epsilon shunt calibration system makes it easy to transfer epsilons. It is a common technique to use shunt resistors to check strain gauge measuring systems. Creating shunt calibration values for balances nasa. If needed, expand the node down to enable shunt calibration on multiple channels. Shunt cal is short for shunt calibration, and is a method for determining the fullscale output of a pressure transducer by electrically simulating a fullscale load.
Because of their size and the pressure ranges they handle, shunt cal is the only safe way to test a hammer union in the field. Shunt calibration of a strain gauge load cell instrumentation. The keysight 34330a current shunt is a precision 0. Shunt calibrations ensure accurate strain measurements by adjusting the sensitivity or gain of the data acquisition equipment to compensate for leadwire resistance and other scaling errors. Strainsmartdata acquisition software for stress analysis testing. Shunting and checking using the shunt signal provide many benefits and can significantly reduce calibration effort. Computer software custom designed to control the instron load frame, acquire data and perform shunt calibration and data analysis, generate a calibration report, and save the data in a database for future reference with one button touch.
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