From the measurements menu, you can select from these four measurement types.
PIM versus Time
This measurement tracks instantaneous PIM and also records Peak PIM levels throughout a fixed frequency PIM test. It is useful for dynamic PIM tests and provides a visual indication of the stability of the system under test.
Noise Floor
Two different Noise Floor measurements are available to evaluate Rx interference sources before making a PIM measurement. For each measurement, Tx power is Off. The Time View measurement allows you to check for external interference at the IM frequency that is being measured. The Spectrum View measurement allows you to view interference levels across the current Rx frequency range.
The IM products of interest are in the same frequency range used by mobile users equipment to communicate with base stations. It is therefore possible for nearby mobile equipment to generate signals that are powerful enough to interfere with your PIM measurement. The Noise Floor measurement mode graph area displays Noise Floor Measurement message:
Noise Floor Measurement Message
Distance‑to‑PIM
Distance‑to‑PIM (DTP) is similar to Distance‑to‑Fault (DTF), which Anritsu introduced in the Site Master for identifying the location of impedance mismatches in a feed line. DTP quickly and accurately identifies the location of PIM faults inside the feed system as well as beyond the antenna.
Distance‑to‑PIM is a swept measurement that enables identification of the location of multiple PIM sources in the RF path. Distance‑to‑PIM is an analysis feature only, and it should not be used as a pass / fail test.
Swept PIM
PIM measurements are the vector sum of all PIM signals that are generated on a line at the tested IM frequency. When multiple PIM sources exist, it is possible for the signals to combine out-of-phase at a particular test frequency to indicate a passing result when the individual PIM levels are actually failures. A Swept PIM test varies the IM frequency over a range of frequencies so that you get a clearer picture of the true, system PIM performance.
2-Port Measurement
Two-port measurements can be made in PIM vs Time, Distance to PIM, and Swept PIM modes. These modes display the message 2-Port Measurement in the graphing area of the screen. Refer to the PIM Analyzer Measurement Guide listed in Other Documents.
2-Port Measurement Mode Message
Adding a Limit Line
1. Press the Shift key and then the Limit (6) key.
2. Press the Limit (Upper / Lower) submenu key to select the desired limit line, Upper or Lower.
Note
The upper limit must be On in order to use the Limit Alarm or the Pass Indicator.
3. Activate the selected limit line by pressing the On Off submenu key so that On is underlined.
4. If necessary, press the Set Default Limit submenu key to redraw the limit line in view.
5. Press the Amplitude submenu key to set the Limit value.
6. Press the Limit Alarm submenu key to toggle the alarm setting On and Off. The current setting is underlined.
Although the instantaneous PIM values may be displayed in white numerals at the end of a measurement, if the measured PIM value exceeded the upper limit setting at any time during the measurement, then the Peak PIM values will remain displayed with red numerals when the measurement is complete.
