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Digital Panel Meter: Measuring Accuracy When Measuring Circumferential Speed

FAQ No. FAQ00705

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Question

What is the measuring accuracy when measuring circumferential speed with the K3NR Digital Panel Indicator?

Answer

Answer

The measuring accuracy for K3NR operating mode 1 (rotational/circumferential speed) is ±0.006% rdg ±1 digit. If the variation of input pulses is not considered, the error depends on the number of significant digits displayed below the decimal point. The error is the error in the read value.

Example 1: Error When Displaying 85.000 km/h


Calculation: 85.000 km/h × (0.006%) = ±0.0051 km/h

In this case, three digits are displayed below the decimal point, so the fourth digit below the decimal point in ±0.0051 km/h is rounded off to yield an accuracy of ±0.005 km/h. There is also an error of ±1 added to the rightmost digit (±0.001 km/h) for a total error of ±0.005 km/h ±0.001 km/h = ±0.006 km/h. Consequently, the display may vary between 84.994 and 85.006 km/h.

Example 2: Error When Displaying 85.00 km/h

Calculation: 85.000 km/h × (±0.006%) = ±0.0051 km/h

In this case, two digits are displayed below the decimal point, so the third digit below the decimal point in ±0.0051 km/h is rounded off to yield an accuracy of ±0.01 km/h. There is also an error of ±1 added to the rightmost digit (±0.01 km/h) for a total error of ±0.01 km/h ±0.01 km/h = ±0.02 km/h. Consequently, the display may vary between 84.98 and 85.02 km/h.

Example 3: Error When Displaying 85.0 km/h


Calculation: 85.000 km/h × (±0.006%) = ±0.0051 km/h

In this case, one digit is displayed below the decimal point, so the second digit below the decimal point in ±0.0051 km/h is rounded off to yield an accuracy of ±0.0 km/h. There is also an error of ±1 added to the rightmost digit (±0.1 km/h) for a total error of ±0.0 km/h ±0.1 km/h = ±0.1 km/h. Consequently, the display may vary between 84.9 and 85.1 km/h.