668337
37
Zoom out
Zoom in
Previous page
1/52
Next page
Elma BM 251-252-255-257
side 37
Analog bar-graph
The analog bar graph provides a visual indication of measurement like a traditional analog
meter needle. It is excellent in detecting faulty contacts, identifying potentiometer clicks,
and indicating signal spikes during adjustments.
Average sensing RMS calibrated
RMS (Root-Mean-Square) is the term used to describe the effective or equivalent DC
value of an AC signal. Most digital multimeters use average sensing RMS calibrated
technique to measure RMS values of AC signals. This technique is to obtain the average
value by rectifying and filtering the AC signal. The average value is then scaled upward
(calibrated) to read the RMS value of a sine wave. In measuring pure sinusoidal waveform,
this technique is fast, accurate and cost effective. In measuring non-sinusoidal waveforms,
however, significant errors can be introduced because of different scaling factors relating
average to RMS values.
True RMS
True RMS is a term which identifies a DMM that responds accurately to the effective RMS
value regardless of the waveforms such as: square, sawtooth, triangle, pulse trains,
spikes, as well as distorted waveforms with the presence of harmonics. Harmonics may
cause :
1) Overheated transformers, generators and motors to burn out faster than
normal
2) Circuit breakers to trip prematurely
3) Fuses to blow
4) Neutrals to overheat due to the triplen harmonics present on the neutral
5) Bus bars and electrical panels to vibrate
Crest Factor
Crest Factor is the ratio of the Crest (instantaneous peak) value to the True RMS value,
and is commonly used to define the dynamic range of a True RMS DMM. A pure
sinusoidal waveform has a Crest Factor of 1.4. A badly distorted sinusoidal waveform
normally has a much higher Crest Factor.
NMRR (Normal Mode Rejection Ratio)
NMRR is the DMM's ability to reject unwanted AC noise effect that can cause inaccurate
DC measurements. NMRR is typically specified in terms of dB (decibel). This series has a
NMRR specification of >60dB at 50 and 60Hz, which means a good ability to reject the
effect of AC noise in DC measurements.
CMRR (Common Mode Rejection Ratio)
Common mode voltage is voltage present on both the COM and VOLTAGE input terminals
of a DMM, with respect to ground. CMRR is the DMM's ability to reject common mode
voltage effect that can cause digit rolling or offset in voltage measurements. This series
has a CMRR specifications of >60dB at DC to 60Hz in ACV function; and >120dB at DC,
37


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Elma BM252 at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Elma BM252 in the language / languages: English, Danish, Swedish, Norwegian as an attachment in your email.

The manual is 4,89 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info