CALIBRATION OF MEMBRANE FILTER

Gas Chromatography
Most of our analyses use one or more of the following Gas Chromatographic techniques: GC/|FID, GC/MFID, GC/TCD, GC/HID and GC/MS.

Each of these techniques use gas or liquid standards that are purchased as NIST traceable.
Each of these techniques use 2 – 6 calibration standards to develop a calibration plot.
Calibrations plots are performed in each analytical queue in order to develop the calibration plot.
Each run includes a QA check standard that is run in duplicate.

Analytical Balance
We determine the mass of particulate and oil mist in client’s samples by gravimetry. We use an analytical balance to weigh the filters before and after the air sample is submitted.

The analytical balance is checked for calibration with an internal calibration weight, and 2 external calibration weights (1.0000 grams and 10.0000 grams).

Oil Mist: Trace and Ultra-trace levels
We determine ordinary oil mist (down to 0.3 mg/m3) by gravimetry, and ultra trace oil mist (0.005 mg/m3) by extraction/GC. There is no consensus agreement for an oil mist standard, so we use 3 levels of Chemlube 751 for calibration.

Sampling Kit Calibration
The volume of air flowing through the analytical filter (determination of oil mist + particulate) is determined by the back pressure at the filter and the length of time that air flowed through the membrane filter. The pressure gauges are calibrated for flow with a filter in place, and a flow meter (Blue White Industries 2 – 20 ). The flow meter is calibrated to cover the range of 2 – 20 scfm, but we only use the range of 4 – 19 SCFM. (A Calibration plot for air flow is attached.)

Accreditation
We are accredited by American Industrial Hygiene Association (AIHA) for analysis of compressed air. Our certification # is 102116.

We are also approved by the US Navy (NAVSEA) for the analysis of life support gases.

We are a charter member of C.A.P.T.; along with each CAPT member, each quarter we receive a double-blind unknown which we analyze to determine our level of proficiency. The test compounds consist of Oxygen, Carbon monoxide, carbon dioxide, methane, TVHC, and ethane. Our proficiency is 100%, and the average result of our test scores is 97 – 101 % or higher.

If you have questions call or email us: dhe0124@aol.com

David H. Elgas
President, Analytical Chemists, Inc.

C:\ Air program\Literature\Calibration of membrane filters Oct 12

ANALYTICAL CHEMISTS, INC.
7551 Convoy Court, San Diego, CA 92111 24hr Voice & FAX (858) 560-4916

Client:: San Onofre

Date : October 12, 2006
Model: Dedicated SCUBA Sampler
S/N : P-1033

Pressure at Red gauge, unrestricted
Flowmeter
type
Flow
SCFM

10 psig Gilmont #13 rotameter
5.8

15 psig Gilmont #13 rotameter
7.8

20 psig Gilmont #13 rotameter
9.2

25 psig Gilmont #13 rotameter
11.0

30 psig Gilmont #13 rotameter
12.5

35 psig Gilmont #13 rotameter
14.5
See Also calibration Plot

Dräger Color tube adapter: RD2-106
Serial Number : 4001

Compound
Flowmeter
type
Target Flow
cc/min
Actual findings
cc/min + 5%

Carbon Monoxide
Soap film
200
200

Carbon Dioxide
Soap film
200
200

Moisture Gilmont #13 rotameter
5000
5000

Oil Tube Gilmont #13 rotameter
5000
5000