PNC and VPR ValidationPMP Meeting 30th March 2009

Jason Southgate & Ian Marshall

Objective

To test the practicalities of undertaking the validation of particle

number counters (PNC) and volatile particle removers (VPR), as

specified in the PMP procedures, at a user’s premises rather than

within a specialist aerosol science laboratory.

All the necessary aerosol generation and measurement equipment

was transported to a third party’s premises and the validation was

carried out within their facilities.

PNC Validation

A local PNC (TSI model 3010D) was compared with a reference

PNC (TSI model 3010, s/n 2005) in accordance with the method

described in the PMP Particle Number Counter Calibration

Procedure (ED47382/PNC, Version 5, December 2007).

Sodium chloride test particles were used in the electrical mobility

diameter range from 70 to 100 nm and the concentration range

from ~700 to ~9,900 particles cm-3.

Particle generation was by an evaporation/condensation method.

PNC Validation

y = 0.9283x

R2 = 0.9979

0.E+00

1.E+03

2.E+03

3.E+03

4.E+03

5.E+03

6.E+03

7.E+03

8.E+03

9.E+03

1.E+04

0.E+00 1.E+03 2.E+03 3.E+03 4.E+03 5.E+03 6.E+03 7.E+03 8.E+03 9.E+03 1.E+04 1.E+04

Reference PNC (TSI 3010 s/n 2005, # cm-3)

Te

st

PN

C (

TS

I 3

01

0D

, #

cm

-3)

VPR Validation

A local VPR (Matter Engineering) was validated in accordance with the

method described in the PMP Volatile Particle Remover Calibration

Procedure (ED47382/VPR, Version 5, December 2007), using:

• 91 nm NaCl particles to provide a comparison with existing calibration data from

CAST generated particles (PND1 80°C, ET 300°C, PND2 DR 1).

• 100, 50 and 30 nm NaCl particles across a range of dilution settings (PND1 150°C,

ET 300°C, PND2 DR~12).

• tetracontane particles to determine the volatile particle removal efficiency (single

PNC method).

Particle generation was by an evaporation/condensation method.

VPR Validation – NaCl/CAST @ 91 nm

0

50

100

150

200

250

300

350

400

450

500

0 20 40 60 80 100 120

Potentiometer Setting (%)

PC

RF Carbon 80°C

NaCl 80°C

VPR Validation – NaCl/CAST @ 91 nm

y = 0.0007x

R2 = 0.9997

y = 0.0005x

R2 = 0.9998

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0 20 40 60 80 100 120

Potentiometer Setting (%)

1/(

PC

RF

)

Carbon 80°C

NaCl 80°C

VPR Validation – NaCl @ 100, 50 & 30 nm

0

2000

4000

6000

8000

10000

12000

0 20 40 60 80 100 120

Potentiometer Setting (%)

PC

RF 100 nm

50 nm

30 nm

VPR Validation – NaCl @100, 50 & 30 nm

y = 4E-05x

R2 = 0.9955

y = 4E-05x

R2 = 0.9957

y = 2E-05x

R2 = 0.9758

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

0.0045

0 20 40 60 80 100 120

Potentiometer Setting (%)

1/(

PC

RF

)

100 nm

50 nm

30 nm

VPR Validation – NaCl/CAST Comparison

y = 0.0007x

R2 = 0.9997

y = 0.0006x

R2 = 0.9955

y = 0.0005x

R2 = 0.9998

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0 20 40 60 80 100 120

Potentiometer Setting (%)

1/(

PC

RF

)

Carbon 80°C 91 nm

NaCl 150°C 100 nm

NaCl 80°C 91 nm

VPR Validation - PCRF

Particle Concentration Reduction

Factors

Potentiometer

Setting

(%) fr(100 nm) fr(50 nm) fr(30 nm)

)100(

)50(

nmf

nmf

r

r )100(

)30(

nmf

nmf

r

r

100 244 270 530 1.10 2.17

34 643 891 1234 1.38 1.92

23 923 1382 1676 1.50 1.82

12 1839 2692 3762 1.46 2.05

5 4634 6028 11416 1.30 2.46

VPR Validation – Volatile Removal

Concentration

(cm-3)

Particles Counted

Upstream 16,256 2,709,323

Downstream

Room Temperature VPR 3,220 536,733

Downstream

Heated VPR 3 47,360

Conclusions

The performance of the PMP validation procedures at a user’s premises is a practical proposition.

The PNC under test met the acceptance criteria when compared with a reference PNC using sodium chloride test particles.

The VPR under test met the acceptance criteria for volatile removal efficiency using tetracontane test particles.

Sodium chloride particles of 50 and 30 nm diameters did not penetrate the VPR with the expected efficiency, which resulted in particle concentration reduction factors that were significantly greater than anticipated.

Are sodium chloride particles of these diameters generated in this way stable under the temperature conditions experienced within the VPR?