Cilas, for most of its sensitive to contamination applications, exploits its Non-Volatile Residues Measurement Bench in compliance with ASTM E-1235-01 recommendations (American Society for tests and materials).

This method can be used to proceed to a quantitative analysis by differential weighing of the molecular contamination extracted from a surface with a solvent (Non-Volatile Residues: NVR).

By determining the overall contribution of organic pollutants, this method differs from IRTF detection methods used in the space industry involving a measure of identified and known contaminants.

The analyses are based on the retrieval of a leachate coming from an identified surface, and on successive concentration phases until a sample volume tailored to the required level of precision is obtained.

The level of precision obtained allows to quantify traces of molecular pollutants at concentrations inferior to two fiftieth of a microgram per square centimeter (0,04 µg/cm²).

These concentration steps established inside suitable equipment can be used to constantly monitor critical parameters in order to preserve results from false positive or negative.

Application

Checking surface molecular cleanliness.
Confirming the remaining level of contamination after cleaning.
Confirm decontamination processes efficacy.
Validating production methodologies.
Track contamination trend.

Characteristics

Sample volume: 1.5 ml- 500 ml.
Adjustable and regulated vacuum: 2 mbar - 900 mbar.
Evaporation temperature: until 95°C by 1°C steps.
Time of analysis: about 4 hours.
Response calibration: Internal preparation of standards for validity confirmation.

Performances

The measurement method can be used to analyze extracted contaminations from 10 µg up to 5 g with an incertitude of +/-8 μg.

For surfaces of 1000 cm² as detailed in the ASTM E-1235-01, the operating range is as follows:
from 0.08.10-7 g/cm² to nearly 5 g/cm²
precision: +/-8.10-9 g/cm².

Automatic control

Traceable calibration of each equipment.
Traceability of retrieval solvents.
Automatic control routines to avoid contamination and drifts.
Preparation of internal standards to confirm the bench response and the strict application of operating procedures.

Correlation of standards measurements to measured values

Value expected for prepared standards (in μg)

Value obtained for standards submit to analysis