Measurement Errors in Physics 517/617 As you learned in Physics 416 knowing the error in a measurement is necessary to analyse, fit, and compare your measurements to theory. It is the responsibility of an physicist/engineer to compare data to theory as completely as possible. It is obvious that full blown error analysis on most of the physics 517 /617 labs would take more time than warranted. Unfortunately it is impossible to make comparisons between data and theory without knowing the errors in your readings. The following values were taken from the technical specifications for your equipment. In the specifications the values are referred to as “accuracy” which correctly identifies the errors as systematic in nature. Example: How to calculate the Error Say one measure the resistance of a resistor using a Fluke 75 multimeter as 148.5 KΩ. The corresponding error is ±(0.005*148.5+0.2)=0.94. Here the +0.2 comes from 2 counts of the least significant digit (LSD). Your measurement is then 148.5±.9 KΩ.

Fluke Meter Technical Specifications

DC V Voltage Error (σσσσ):

Fluke 75: ±(0.5% of reading + 1 counts (LSD))

Fluke 175: ±(0.15% of reading + 1 count (LSD))

AC V Voltage Error (σσσσ):

Fluke 75,175: ±(2% of reading + 2 counts (LSD))

DC A Current Error (σσσσ):

Fluke 75,175: ±(1.5% of reading + 2 counts (LSD))

AC A Current Error (σσσσ):

Fluke 75,175: ±(1.5% of reading + 2 counts (LSD))

Resistance ΩΩΩΩ Error (σσσσ):

Fluke 75: ±(0.5% of reading + 2 counts (LSD))

Fluke 175: ±(0.9% of reading + 2 digits (LSD))

Oscilloscope Technical Specifications

Voltage

(average of ≥ 16

waveforms)

Voltage Error (σσσσ):

TDS200: ±(4% of reading + 0.1div + 1mv)

TDS1002: ±(3% of reading + 0.1div + 1mv)

Time

(average of ≥ 16

waveforms)

Time Error (σσσσ):

Fluke 75,175: ±(1 sample interval +100pps of reading)

LRC Meter Technical Specifications

BK 875A Capacitance Capacitance Error (σσσσ):

< 2nf ±(3% of reading + 1 counts(LSD)) 2nf-2µF ±(2% of reading + 1 counts(LSD))

>2µF ±(3% of reading + 1 counts(LSD))

BK 875A Inductance Inductance Error (σσσσ):

<2mH ±(3% of reading + 1 counts(LSD))

2mH-200mH ±(2% of reading + 1 counts(LSD))

2H-20H ±(3% of reading + 1 counts(LSD))

200H ±(5% of reading + 1 counts(LSD))