limit line
A test limit made up of a series of line segments, positioned according to frequency and amplitude within the analyzer measurement range. Two defined limit lines may be displayed simultaneously. One sets an upper test limit, the other sets a lower test limit. Trace data can be compared with the limit lines as the analyzer sweeps. If the trace data exceeds either the upper or lower limits, the analyzer displays a message or sounds a warning, indicating that the trace failed the test limits.
limit-line file
The user-memory file that contains the limit-line table entries. Limit lines are composed of frequency and amplitude components that make up a trace array and this data is stored in the file. The limit-line file feature is available on analyzers that are capable of limit-line operation. Refer also to limit line.
limit-line table
The line segments of a limit line are stored in the limit-line table. The table can be recalled to edit the line segments, then restored in the limit-line file. Refer also to limit line.
linear display
The display mode in which vertical deflection on the screen is directly proportional to the voltage of the input signal. The bottom line of the graticule represents 0 V, the top line represents the reference level. The reference level is a non-zero value characteristic to the analyzer model. On the HP 140 series analyzers, select a specific scale factor in volts per division. On newer models of analyzers, select the reference level. The scale factor becomes the reference level value divided by the number of graticule divisions. Although the display is linear, analyzers with microprocessors allow reference level and marker values to be indicated in dBm, dBmV, dBpV, volts, and in some cases, watts.
linear input level
The maximum input-signaI level where gain compression does not occur. Refer also to gain compression.