Digital Multi-Meter to measure pulse of a flowmeter - Page 1
Forum section: electronics / testgear

author: xstarlogic
author_rank: Newbie
timestamp: September 06, 2024, 05:30:21 pm
content: Hello all,I need to measure the frequency emitted by the flowmeter. The flowmeter transmits data 0 to 12kHz with an amplitude of 17 DC Volt.I have been looking into some digital multi-meter reviews. Most do not have a review regarding on frequency reading. If some frequency reading is included in the review, all use sinusoidal waveform of AC power source.I do not want to use an oscilloscope, which will be more expensive. For safety reason, I wanted to carry less stuff climbing to 10 meter or above. and most instrument are using 4-20 DCmA, so it will be troublesome to carry lots of things while climbing up.I've been looking at some low budget multi-meter brand available in my country, such as ANENG and ZOYI. Brymen is not available, UNI-T is available but most are expensive. Fluke is not my best choice. I am currently looking at ZOYI-102L but have no idea will the frequency work for 17 DCV.I am newbie to electrical frequency, please provide me with basic explanation.Many thanks to all

author: HKJ
author_rank: Super Contributor
timestamp: September 06, 2024, 05:38:45 pm
content: Check my reviews, I do test the frequency input on DMM's:Generally meters is not designed for sinus waveforms, but for square wave. If the amplitude of the sinus is large enough it will be counted.

author: HKJ
author_rank: Super Contributor
timestamp: September 06, 2024, 05:44:56 pm
content: If you want to count the actual number of pulses, you have a problem. Very few meters can do that, I only know of some Gossen, but they are very expensive.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 06, 2024, 05:50:06 pm
content: Is the FNIRSI SG003 / SG004 in your budget range? These are low-cost process calibrators, so their main functionality is generating signals. But they also have a quite good input side with frequency and PWM display.They also allow you to choose between logic signal or open collector detection - that´s a feature I´ve never seen at any DMM or frequency counter.And they´re small - perfect for field use.

author: xstarlogic
author_rank: Newbie
timestamp: September 07, 2024, 04:07:06 pm
content: QuoteWhere to see your review? I'm still new around here, and may get lost very easy.I think pulse produced by flowmeter is a square waveform as they are intercepted by DI module of PLC.QuoteNo, I'm not looking for calibrator or generator. Please read my question carefully.

author: HKJ
author_rank: Super Contributor
timestamp: September 07, 2024, 04:10:57 pm
content: Quote from: xstarlogic on September 07, 2024, 04:07:06 pmClick on the globe under my name will bring you close.A more direct link:https://lygte-info.dk/info/indexDMMReviews%20UK.html

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 07, 2024, 05:15:53 pm
content: Quote from: xstarlogic on September 07, 2024, 04:07:06 pmPlease read my answer carefully. The SG03/04 have a meter and a generator function. And the meter is capable of measuring frequencies, counting pulses and measuring PWM.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 07, 2024, 06:31:20 pm
content: I don't know I would assume all DMM with frequency measurement function can do that. I have used the following DMM to measure frequency Fluke 87V, 189, 287, 289, 45 and all can measure pulses. Although the kind of pulses I have are either 5V or 12V or 24V (not 17V but I don't think 17V would make a difference). And yes they are all square wave pulses.

author: HKJ
author_rank: Super Contributor
timestamp: September 07, 2024, 09:01:21 pm
content: Quote from: BeBuLamar on September 07, 2024, 06:31:20 pmThere are differences in how they trig, some requires a zero crossing, some do not.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: September 07, 2024, 09:34:29 pm
content: Quote from: Phil1977 on September 07, 2024, 05:15:53 pmThey are quite versatile, though only the SG004A got the frequency reading (in/out) just as MR9270S, while SG003A only got (out).Flow meter example from +9.10min

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 08, 2024, 12:02:54 am
content: Quote from: HKJ on September 07, 2024, 09:01:21 pmAll of the signals I mentioned are not zero crossing. They are 0 to 5, 12 or 24V pulses.