I would like to know your perspective on the following:
When measuring 24VDC both the lower test limit (LTL) and the upper test limit (UTL) are defined by either product, safety or 'common' specifications (the latter are chosen limits by company standards). Lets say for example that the 24VDC is tested passed if it measures between 21.6V and 26.4V, i.e. 10% tolerance.
The measured values can be represented by this matrix for 6 measured values at 6 different points in time: [23.2, 22.95, 23.4, 24.0, 23.5, 23.0]
The 'chosen' limits mark one result as FAIL, the 22.95V.
Lower the LTL to 22V, but keep the UTL at 25V to protect the applied product. Results in asymmetrical limits
Lower the LTL to 22V, but also raise the UTL to 26V to balance the tolerance.
Results in possible product failure (critical limit may be 25V)
Both approaches are approved by the customer. The product using this 24VDC is not known.
How would you deal with this situation?