2.3 Specific Gravity

Question 1

SG is not anymore routinely determined as part of physical examination

T or F

Answer 1

T

Question 2

Normal values for Random SG?

Answer 2

1.003 - 1.035

Question 3

Normal values for 24hr/average

Answer 3

1.010 - 1.025

Question 4

Methods in detecting SG:

Based on refractive index measurement

a. Urinometry
b. Refractometry
c. Harmonic Oscillation Density

Answer 4

b

Question 5

Methods in detecting SG:

Principle employed by Yellow IRIS (old machine; phased-out)an indirect measurement of density based on the change in frequency of sound waves oscillating on urine

a. Urinometry
b. Refractometry
c. Harmonic Oscillation Density

Answer 5

c

Question 6

In Harmonic Oscillation Density:

Sound waves decreases proportionally to urine SG

T or F

Answer 6

T

Question 7

Methods in detecting SG:

Based on density measurement that is less accurate than other measurement

a. Urinometry
b. Refractometry
c. Harmonic Oscillation Density

Answer 7

a

Question 8

Methods in detecting SG:

Has a need for corrections in the reading of temp and the presence of glucose and proteins

a. Urinometry
b. Refractometry
c. Harmonic Oscillation Density

Answer 8

a

Question 9

What is the calibration temp for urinometry?

Answer 9

20 C

Question 10

Refractometry is not affected by temp

T or F

Answer 10

T

Question 11

In refractometry, It can measure Up to >1.040 SG

T or F

Answer 11

T

Physiologically impossible

Question 12

Distilled water is 1.000

a. Urinometry
b. Refractometry

Answer 12

a and b

Question 13

Distilled water with St’d (NaCl)

a. Urinometry
b. Refractometry

Answer 13

b

Question 14

In refractometry:

3% NaCl_______
5% NaCl_____
7% NaCl______
9% Sucrose_______

What is the SG?

Answer 14

1.015 +/- 0.001
1.022 +/- 0.001
1.035 +/- 0.001
1.034 +/- 0.001

Question 15

In urinometry:

What is the SG for Potassium sulfate? (K2SO4)

Answer 15

1.015

Question 16

Volume used: 15mL

a. Urinometry
b. Refractometry

Answer 16

a

Question 17

Volume used: 1-2 drops

a. Urinometry
b. Refractometry

Answer 17

b

Question 18

In urinometry, if the urine temp is higher than the calibration temp (20C) what is the correction?

Answer 18

+0.001/3C difference

Question 19

In urinometry, if the urine temp is Lower than the calibration temp (20C) what is the correction?

Answer 19

-0.001/3 C difference

Question 20

BOTH urinometry and refractometry, what is the correction for protein and Glucose?

Answer 20

Protein: -0.003 / g/dL
Glucose: -0.004 / g/dL

Question 21

For dilution, you have to account for the extend of dilution by ____________ the last two digits of the specific gravity reading by the dilution factor.

Answer 21

multiplying

Question 22

Dilution ex:

1:2
SG: 1.015
15x2

= 1.030