The correct way to have a DMM read AC V hertz

Thread Starter

abdulbadii

Joined Aug 30, 2017
85
How the correct way to have typical cheap DMM read AC V hertz as it'll display 000 as long as the either/both probe connected and a frequency, here in kilohertz, if it's disconnected, so what is the correct time length of the probe being connected before being lifted/disconnected and DMM gives a read frequency ?

Problem is it seems the frequency given is inconsistent, varies on that time length of the probe being connected and problem too it's shown in short time while the "max/min" feature cannot be applied in this Hertz selection

Please sincerely help of which the correct guide is really appreciated
 

Sensacell

Joined Jun 19, 2012
3,432
Not sure I understand what you are trying to accomplish?
The problem is entirely dependent on the specific DMM you have - they are not all the same.
 

rsjsouza

Joined Apr 21, 2014
383
As others have said, it is entirely dependent on the DMM and the type of signal you have. Some DMMs can measure frequency on the "V~" or have a dedicated "Hz" range (sometimes both). One aspect that is dependent on the equipment is if the signal crosses zero (like the outlet) or not (like a digital signal). The delay in getting the correct frequency may also be due to variations on the signal itself, very low input levels (which confuse the meter) or the time that is needed to actually average several datapoints to get an accurate measurement.

One warning, though: several cheap DMMs have severe voltage limitations on the "Hz" input, which is nowhere near the maximum voltage that can be applied to the "V" range. Read the manual of your equipment that should specify this.
 

Audioguru again

Joined Oct 21, 2019
6,674
A cheap DMM is made to measure levels of DC and only 50Hz or 60Hz. Maybe they so not measure the frequency.
My expensive Fluke DMM reads accurate frequencies to 20kHz and reads accurate levels to 1kHz.
 

schmitt trigger

Joined Jul 12, 2010
872
Problem is it seems the frequency given is inconsistent, varies on that time length of the probe being connected and problem too it's shown in short time while the "max/min" feature cannot be applied in this Hertz selection
This sentence of yours makes no sense. Almost any DMM with a frequency function will provide a Hz reading practically instantaneously. The Fluke meter, for instance, on the rotary selector there is almost always a function labeled V~ Hz. It always defaults to reading AC volts, so when you connect it to the mains line, it will display the AC volts. If you press the second function yellow button, within a blink of the eye it displays the frequency. Push it again, and it again reads AC volts.

Other DMM brands have similar if not identical functionality.
Thus, as others have mentioned, you have to tell us what DMM brand and model are you using.
 
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