Is there an inexpensive DMM with FAST MIN/MAX (NOT just MAX) function? - Page 1
Forum section: electronics / testgear

author: Adam Baum
author_rank: Newbie
timestamp: February 05, 2024, 04:09:18 pm
content: Question in thread title.

author: bdunham7
author_rank: Super Contributor
timestamp: February 05, 2024, 04:34:57 pm
content: Sure. How fast and how inexpensive? You'd need to quantify those attributes to get a meaningful answer.

author: myf
author_rank: Regular Contributor
timestamp: February 05, 2024, 04:38:35 pm
content: Hello,The (old) ut-61e has min and max values.The value read is a very fast transient, not the average over a period (0.5s). I read about 20A or 30A when charging a 4700 µF capacitor with a laptop-type power supply (36V - 4A).

author: Fungus
author_rank: Super Contributor
timestamp: February 05, 2024, 04:42:54 pm
content: What bdunham said, and:What sort of signal are you looking at? What time frame?You can get pocket oscilloscopes for about $30. They haveveryfast min/max over short periods of time.

author: RtBNL
author_rank: Newbie
timestamp: February 05, 2024, 04:58:45 pm
content: Both the Brymen 869 en 789 have a very fast min/max (crest function) they both measure the peaks op(~+ & - 325v] on the wall outlets that give ~230 volts.

author: Adam Baum
author_rank: Newbie
timestamp: February 06, 2024, 11:46:42 pm
content: Quote from: myf on February 05, 2024, 04:38:35 pmI own a Fluke 77 and a Fluke 17B and, of course, the 17B+ has min/max and not the 17B. Rather than spending $188 for a 17B+ just to get that function, I'd like to spend as little as possible.Your UT61E lead got me there, so thanks. It looks like the UT61B+ (with min/max) or UT61D+ (with min/max and peak min/max) are the ones to go with. The 250us capture time is the same as with the much more expensive Flukes with min/max.

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 07, 2024, 05:28:29 am
content: Quote from: Adam Baum on February 06, 2024, 11:46:42 pmWhere did you find this spec? I can't find it in the Uni-T UT61+data sheetoruser manual.

author: jfiresto
author_rank: Frequent Contributor
timestamp: February 07, 2024, 09:05:48 am
content: If the meter uses a DMM chip, have you checked its datasheet?The datasheet for the Cyrustek ES51962 in my B&K 390A quotes a worst case error for a 10µs pulse of +/-2% + 25 counts.

author: Adam Baum
author_rank: Newbie
timestamp: February 08, 2024, 06:08:31 pm
content: Quote from: mwb1100 on February 07, 2024, 05:28:29 amSomewhere in this section on their slow as snot web page :https://meters.uni-trend.com/services-support/faqs/"For peak measurement: Maintain the MAX/MIN value of pulse signal automatically, the response time of logging MAX/MIN peak value is short (about 250us), a transient value can be measured accurately through this function."The Fluke figure came from here:https://www.fluke-direct.com/pdfs/resources/fluke/How-to-use-Fast-Peak-Min-Max-on-your-DMM-usd.pdfThe FAST MN/MX (187, 189) or Peak Min/Max (87V) function is restricted to the voltage and current measurement. FAST MN/MX or Peak Min/Max can be used to capture intermittent or transient events that occur on a monitored signal over time. Events as short as 250 μs (or longer) can be captured...

author: rsjsouza
author_rank: Super Contributor
timestamp: February 08, 2024, 06:40:06 pm
content: In my tests with peak mode at a low level (5V), the UT61E (non plus) was the champ (1us) when compared to all others.I did a video comparing several meters (in portuguese, sorry), Skip to 13:58 for the UT61E.