Summary: In this exercise, the objective is to reduce noise in analog measurements by averaging.
EXERCISE 1
- Run the Voltmeter VI.
- Introduce noise into the temperature measurement by changing the
Temp Sensor Noiseswitch on the DAQ Signal Accessory to theONposition. The measurements begin to fluctuate with noise spikes.
1.A) Block Diagram
- Stop the VI and display the block diagram. Modify the block diagram to calculate the average of 100 measurements.
Figure 1 Place the
CollectorExpress VI located on theFunctions>>Signal Manipulationpalette, on the block diagram. This Express VI creates an internal buffer to store the individual points. When the maximum number of input points is collected, the Express VI discards the oldest points and adds the newest points. In theConfigure Collectordialog box that appears, set theMaximum number of samplesto100. Click theOKbutton to close the dialog box.Place the
StatisticsExpress VI, located on theFunctions>>Analysispalette, on the block diagram. In theConfigure Statisticsdialog box that appears, place a checkmark in theArithmetic Meancheckbox to perform averaging on the collected data. Click theOKbutton to close the dialog box.- Select
File>>Save Asto save the VI asMeasurement Averaging.viin theC:\Exercises\LabVIEW Basics Idirectory. - Display the front panel and run the VI. Notice that the noise spikes are reduced when the
Temp Sensor Noiseswitch is turned on. - Stop and close the VI.
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