Product category:
Stand-Alone Instruments
News Release from: Fluke (UK) | Subject: 110/170/180 Series DMMs
Edited by the Electronicstalk Editorial
Team on 21 May 2002
DMMs feature true-RMS measurements
All new ranges of Fluke digital multimeters feature true-RMS measurements, vital for correct fault finding in circuits with nonlinear loads, such as office equipment PSUs and variable-speed drives.
All new ranges of Fluke digital multimeters (DMMs) feature true-RMS measurements, vital for correct fault finding in circuits with nonlinear loads, such as office equipment power supplies and adjustable speed drives 'Average responding' DMMs that simply scale average values of rectified signals may provide measurements which are up to 40% or more in error
This article was originally published on Electronicstalk on 2 Jan 2001 at 8.00am (UK)
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Fluke has released three new series of true-RMS DMMs over the past 12 months.
The 110 Series, the 170 Series and the 180 Series offer a range of features and functions for virtually every application.
Starting at only GBP 75 for the Fluke 110, the new range of products brings Fluke rugged reliability plus true-RMS measurement to all price points in the range of professional DMMs.
Each of the ranges has varied accuracy and resolution - up to 0.025% basic DC accuracy with 50,000 counts of resolution for the 180 Series.
All series conform to international safety categories and offer min-max readings.
The clear readouts feature an analogue bargraph and most models offer backlit displays for easy reading in any environment.
Nonlinear loads, such as adjustable speed drives, PCs and other office equipment, draw distorted current waveforms which in turn will produce a distorted voltage waveform.
'Average responding' meters use the simplest calculation of the RMS (root mean square) value.
They rectify the signal, determine the average value and scale up the result by a fixed multiple, fine for a perfect sinewave.
Using the calculated method an 'average responding' meter may calculate and display RMS readings which are up to 40% too low.
This can be very misleading to the fault-finding technician.
The Fluke 110, 170 and 180 Series DMMs all use an electronic measurement technique, with sufficient bandwidth to cope with mains harmonics, to provide the real effective RMS value of an alternating current. Request a free brochure from Fluke (UK) ...
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