Assignment #1

Analog and Digital Measurements

(EE 300/EE307)

Assignment #1 Oct. 4th, 2015--- Due date Oct-18th-2015

Q1 Define the term Metrology based on International Bureau of Weights and Measures (BIPM)

and International Organization of Legal Metrology (OIML)

Q2 The figure shows the statistical characterization of two different instruments measuring the same real value a) Which instrument is more precise? b) Which instrument is more accurate? c) Which instrument we should choose and why?

Q3 Unit Conversion a) Convert 12.5 cm into mm b) Convert 829 cm into km

c) Convert 42.5 km into cm

d) A rectangular piece of paper of size 841 mm × 1189 mm (A0 size) is to be divided into

16 equal A4 sized sheets. What are the dimensions of the sixteen A4 size papers?

e) Determine the weight of an A4 sheet made from 80 gr/m2 paper?

Q4 A current of I = 3.2 mA has to be measured with a 4 digits instrument with the

following characteristics:

a) Calculate the accuracy in mA, and the relative accuracy for each range.

b) Write the result shown in the display of the instrument in each range.

c) Which range should be chosen to measure the resistance and Why?

Q5 The characteristics of a hydrogel-based pH sensor is given in table below. The output

resolution of this sensor is 0.005 mV.

Input

(ph)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

V0

(mV)

2.25 2.25 2.25 2 2.5 3 3.5 4 4.5 5 5.5 6 6.25 6.25 6.25

The ph values of some liquids:

Distilled water (7.0), Acids (0-7), Alkalines (7-14) Milk (6.6), Coffee (5.0), Orange juice

(3.7), Fruit vinegar (3.2), Cola beverages (2.8)

(a) Plot output V0 vs input ph (b) Determine input range and span

(c) Determine output range and span

(d) What is the “ideal” (linear) operation range of this sensor

(e) Determine the line equation that represents the input-output relationship over the operating range in (d).

(f) Determine sensitivity and bias

(g) Determine input resolution

(h) Considering the entire pH range and using the equation you got in part (d), at what pH

value does the sensor exhibit maximum nonlinearity?