VOCs

Question 1

What test is used for emission of VOCs?

Answer 1

Oddy test: accelerated ageing test.

Question 2

What is the procedure followed in the Oddy test?

Answer 2

1. Material enclosed in sealed glass boiling tube.

Question 3

What materials were used in the Oddy test, and what dimensions?

Answer 3

1. Pb
2. Cu
3. Ag
4. Analar (99.5% pure or better)
   Dimensions: 10x15x0.1 mm

Question 4

Give one way (1) the corrosion of the metal coupons is accelerated.

Answer 4

1. Ratio of material to airspace higher than expected in case or storage.
   - concentration of Volatile corrosive gases higher.

Question 5

Give one way (2) the corrosion of the metal coupons is accelerated.

Answer 5

2. Metal coupon abraded to expose reactive metal surface.
   - small hole pierced in coupon
   - nylon monofilament threaded through hole and tied in place.

Question 6

Give one way (3) the corrosion of the metal coupons is accelerated.

Answer 6

• Sample added to boiling test tube (a - 50 cm3), with seal.
• Tube (b - 0.5 cm3) filled with water, stoppered with cotton wool, added to boiling tube (a).
• Raises RH to 100%, accelerates corrosion.

Question 7

Give one way (4) the corrosion of the metal coupons is accelerated.

Answer 7

• Temperature elevated to 60C
• Rate of emission increased
• Accelerates corrosion

Question 8

Give one way (5) the corrosion of the metal coupons is accelerated.

Answer 8

• Control set up for each type of metal
• With metal coupon and water (NO test material)

Question 9

Give one way (6) the corrosion of the metal coupons is accelerated.

Answer 9

• 28 days later test disassembled

Question 10

What are the results obtained from the Oddy test?

Answer 10

Material classified as:
1. Suitable for permanent use (no corrosion)
2. For temporary use - max 6 months (slight)
3. Unsuitable (obvious)

Question 11

What is the equation for the determination of the amount of sorbent recommended?

Answer 11

Q = (Co VN + ES) t / (PC1)

Q: quantity of sorbent
Co: Conc. outdoor pollutant (μg/m3)
V: Volume of air (m3)
N: AER (1/day)
S: exposed surface (m2)
T: minimum number of days pollutant maintained (days)
P: sorption capacity of sorbent (μg/g per μg/m3)

• Large P = better capacity for sorbent to trap pollutants

Question 12

What are the units of P?

Answer 12

μg/g per μg/m3

Question 13

What is the P value for acetic acid?

Answer 13

5.2

Question 14

What is the P value for H2S?

Answer 14

7.5

Question 15

What is the P value for NO2?

Answer 15

7.9

Question 16

What is the P value for O3?

Answer 16

5.2

Question 17

What is the P value for SO2?

Answer 17

5.1

Question 18

What is the effect of acidic environments on lead objects?

Answer 18

Crumble to white powder - ultimate damage.

Question 19

What are A-D strips?

Answer 19

Quick, short-term tests of atmospheric acidity in storage area or showcases.

Question 20

What are the A-D strip levels of Acetic Acid (ppm)?

Answer 20

1: 1-2
1.5: 3 - 5
2: 6 - 8
2.5: 18 - 20

Question 21

What are the colors of each A-D strip level?

Answer 21

0: blue green (good)
1.5: yellow green
2: light yellow green
2.5: yellow (bad)

Question 22

State another method of determining levels of acidity in environments.

Answer 22

Glass dosimeters - Environmental Impact (Glass) Sensor.