User Manual

28 II Ex

Users Manual

Frequency Measurements

For frequency measurements, the Product counts the

number of times the signal crosses a set voltage level

each second.

Table 7 summarizes the trigger levels and applications for

frequency measurements in the ranges of the voltage and

current functions of the Product.

To measure frequency, connect the Product to the signal

source. Next, push G. When you push E, the

trigger slope switches between + and -, as shown by the

symbol at the left side of the display (refer to Figure 9

under "Duty Cycle"). Push D to stop and start the

counter.

The Product autoranges to one of five frequency ranges:

199.99 Hz, 1999.9 Hz, 19.999 kHz, 199.99 kHz, and

>200 kHz. For frequencies less than 10 Hz, the display is

updated at the frequency of the input. Less than 0.5 Hz,

the display can be unstable.

Some guidelines for frequency measurements are:

• If a measurement shows as 0 Hz or is unstable, the

input signal can be below or near the trigger level. To

correct these problems, go to a lower range, which

increases the sensitivity of the Product. In the 

function, the lower ranges also have lower trigger

levels.

• If a measurement is a multiple of what you expect,

the input signal can be distorted. Distortion can

cause multiple triggers of the frequency counter.

Select a higher voltage range to decrease Product

sensitivity and try to repair this problem. You can

also set a dc range to increase the trigger level as a

possible solution. In general, the lowest frequency

shown in the display is the correct one.