What makes an Aircraft


Why are White Horse standards lot numbers incorporated into the part number (with a small alphabetical character)?

White Horse Reference Materials has chosen to identify its products on a 'Series/Lot" basis. Each part number indicates the series and range of analyte concentration. For example, a titanium lot that is dosed for a targeted hydrogen value may have a P/N of "T" (for the base metal Ti) with an added character identifying its concentration range "J" (which compares with a max spec limit of 125ppm).

The added small character ("a" for the first lot) is added to the part number so users do not have to look for a separate lot number to identify which Certificate Of Analysis (COA) corresponds to the standard. The intent is to minimize confusion as to which certificate is specific to the product. The full part number with its incorporated lot identifier is sufficient to uniquely identify and correlate the product with its COA. As long as the label on the bottle matches the CRM part number shown on your COA, then this is all the information you need to identify the CRM for QA purposes.

Why aren't the values printed on the bottle label?

ISO/IEC 17034 prohibits this practice. They want you to keep the Certificate Of Analysis close and handy for the analyst to refer to. Although many users will hand-write the values on the label themselves, some auditors object to this practice.

I get the wrong results when I analyze your standards -why?

Our products have been well characterized and verified by various quality laboratories.

You are likely comparing our materials with a standard from another producer. There may be several reasons for getting bias between two standards. First, check the precision of the standard you are using to calibrate your instrument. If a group of results (min 3) has a larger variance than our samples, it could be that you need to calibrate your instrument with a minimum of 5 samples of the other material. Then, when comparing with our standards, the results should be comparable. (Unless the standard you were using has a bias.)

For Hydrogen bias issues, the two standards may be different masses. The bias you see when comparing two standards may be caused by the difference between their masses.

When using ASTM E1447 for hydrogen analysis, there is a common issue with biased hydrogen results stemming from analyzing different masses of the same material. It is recommended that you keep the mass of each sample, including calibration material within a nominal range +/- 10% (0.20-0.25g) to minimize this issue. (This is an instrument issue, and although ASTM E1447 allows a range of 0.15-0.30g samples, many instruments experience significant bias when analyzing samples in that full mass range.)

My results vary beyond the tolerance of your standards -why?

This is ALWAYS an issue with the instrument. It could be your analysis method setup (even if it was copied from a factory application note), it could be maintenance or repair issues, or it could be your instrument needs an upgrade. Contact us for assistance, we can help you with these issues.

NOTE: Different instrument models have their own inherent precision limitations. Some can be upgraded (some only by WHTS) and some cannot.