The objective of this experiment was to test the accuracy of chosen sensors – magnetic reed switch, photoeye, and thermocouples – by comparing the software collected data to the hand-held instruments through the use of pre-calibrated devices provided by Dorner Manufacturing.
With the conveyor assembled and sensors mounted, the first test ran was verifying belt speed. A pre-calibrated Extech Photo/Contact Tachometer was used to determine actual belt speed. The tachometer had an attached wheel that was placed onto the moving belt and at 30 second intervals the speed was recorded. After 10 minutes testing for belt speed was concluded. Figure 1 shows the belt speed being tested with the tachometer.
Figure [ 1 ]: Conveyor belt speed determination using pre-calibrated tachometer.
The second test ran was verifying bearing and gearmotor temperatures. A pre-calculated Omega T-Type Thermometer was used at 30 second intervals to determine and record temperature measurements for each bearing as well as the gearmotor. After 10 minutes of testing for bearing and gearmotor temperature, testing was concluded. Figures 2 and 3 show the bearing and gearmotor temperatures being tested with the thermometer.
Figure [ 2 ]: Bearing temperature determination using pre-calibrated thermometer.
Figure [ 3 ]: Gearmotor temperature determination using pre-calibrated thermometer.
The final test ran was verifying that the photoeye was sensing objects moving across the belt. The photoeye senses objects when its signal from transmitter to receiver is interrupted. Objects were placed on the moving belt, as shown in Figure 4, to verify part counting.
Figure [ 4 ]: Part counting determination.
Each test was performed to verify that the sensors chosen were operating accurately and in accordance with the pre-calibrated devices. Figure 5 shows the correlation between belt speed and time for the tachometer as well as the software collected data.
Figure [ 5 ]: Belt Speed Measurement Comparison.
Seen in Figure 5, the blue diamonds represent the data collected with the tachometer, and the orange squares and grey triangles represent each spindle speed. Looking closely at the data, it is seen that the tachometer data stays well in line with the drive spindle data. In comparison with the tachometer, this line behavior verifies the accuracy of the magnetic reed switch. The next feature examined was the difference in speeds of each spindle. There is a clear difference in the each spindle speed, however due to imperfections in the belt conditions it was expected that minor slip was to occur. Any slip under five percent…