# Start and end p/v are not calculated in Empower 3 - WKB12728

Article number: 12728

## SYMPTOMS

- Start p/v and end p/v are not being calculated in Empower 3

## ENVIRONMENT

- Empower 3

## CAUSE

The baseline is flat at 0.

## FIX or WORKAROUND

Three things are necessary for calculation of start and end p/v:

- System Suitability must be enabled for the project.
- Either European or All must be selected for the Pharmacopeia type.
- The baseline at the start or end of the peak must not be 0.

The following formula is used to calculate the p/v value:

Start p/v = (height / height start)

End p/v = (height / height end)

height = height of the peak

height start = valley height at the start of the peak

height end = valley height at the end of the peak

Based on this formula, if the baseline/height start/height end is 0, then the denominator in the formula is 0, which cannot be. Consequently, you do not get a value for p/v.

## ADDITIONAL INFORMATION

Enable Calculate Detector Noise and Drift in the Noise and Drift tab of the processing method.