# :MEASure:JITTer:NOISe:PIR?

Noise PI (rms) Commands

- :MEASure:JITTer:NOISe:PIR?
- :MEASure:JITTer:NOISe:PIR:LEVel
- :MEASure:JITTer:NOISe:PIR:STATus?
- :MEASure:JITTer:NOISe:PIR:STATus:DETails?
- :MEASure:JITTer:NOISe:PIR:STATus:REASon?

## Query Syntax

    :MEASure:JITTerN:NOISe:PIR?

Where N identifies one of four possible jitter/noise analyses {1:4}. For example, `JITTer4`.

## Description

Returns the Periodic Interference (PI), which is a measure of the interference that is uncorrelated to the pattern, yet is periodic. Interference caused by a switching power supply is an example of periodic interference. The value is returned for the level specified by `:MEASure:JITTer:NOISe:PIR:LEVel`.

PI (rms) is useful in the case where the PI is of a known distribution. For example, a stress test may be developed in which sinusoidal PI is intentionally injected. Assuming the injected PI is the only PI present, the system can be calibrated using the PI (rms) measurement.