Amprobe 37XR-A - Page 1
Forum section: electronics / testgear

author: fra.gherard
author_rank: Contributor
timestamp: February 24, 2016, 06:41:30 pm
content: Hello, i'm new, i'm from italy.I bought some days ago an Amprobe 37XR-A because i need a good but relative cheap multimeter for work, my boss don't want to buy a new multimeter, so i decided to bought on my own.0.1% DC accuracy, 10.000 count (9999 real, only 4 digit display ) and important for me 0.01 ?A ADC resolution. For 180€ on the paper is a good multimeter, Fluke or HP are more expensive with these features.So, i took the multimeter to work and i tested the instrument. When i tested it with a DC current variable between about 2.3mA and 2.8mA, the display of the instrument seems went crazy. I can't read the value, but if i use the manual range and i set 10.00 mA range the reading is ok.Look this in a video i made with an HP 974A to compare the measurehttps://youtu.be/jIdwG4j0a7EAfter that i contacted the amprobe tecnical support and for them the instrument is ok. They said: "Amprobe models don't have smoothing function display rate, you need a Fluke 87 for this application".This is the signal that i try to measure:https://youtu.be/gb627LI4VkkHP974A, fluke 77, HP34401A don't have any problem to measure it, Amprobe with autorange can't do it.I tried with my other Amprobe AM510 and with wonder it can read the value without any problemhttps://youtu.be/wKYtL_1r5xIIn the video you can see if i use the AVG function the value is quite ok, but with MAX and MIN don't have any sense, my signal don't reach 3.5mA or 1.9mA, but the instrument read this valueI will return the instrument to Distrelec for repair/change, but i think this is a software problem.What do you think about?Please correct my english, i'm still learning. Thanks

author: fra.gherard
author_rank: Contributor
timestamp: February 25, 2016, 05:55:52 pm
content: hitoday i made a new test with multimeter.first i tried with high current, about 4-5 amps for test the stability with the A input. when the current is stable the read is fine, but when the current isn't stable, the multimeter start go crazy. the other 2 multimeter i used, are both fine all time.https://youtu.be/I2F1Bpg2bZwthen i tried to measure a voltage about 50V. when the voltage is stable the reading is fine, when isn't stable the reading was still ok, normal change of the value displayed, but i read it.so the problem is only only on the current input, both mA-A input.tomorrow i will return the instrument. i hope they will change it, and the new works good.

author: Lightages
author_rank: Unknown
timestamp: February 25, 2016, 08:30:02 pm
content: How do you know the value isn't changing between 1.9 and 3.5mA. That is still possibility as it isn't clear from your scope video. Try setting the scope to measure the min and max values to see it sees the same or not. If the meter is reading incorrectly, then yes send it back. There are many more meters in the world to select from.

author: fra.gherard
author_rank: Contributor
timestamp: February 26, 2016, 06:00:01 pm
content: i used the MIN-MAX function on HP974a, and the value did't go over 3mA or under 2mA.for me HP is the reference instrument. 50.000 count, 0.05% precision, calibrated. i tried also with an HP 34401A and the result is the same with the other HP

author: fra.gherard
author_rank: Contributor
timestamp: April 08, 2016, 05:01:00 pm
content: hii have updates.after 1 month waiting, distrelec sent me a brand new multimeter. i tested it immediately, but the problem persist.as you can see here:8 multimeter, some high end, some el chapo china export, but all works fine except the amprobe.this time i returned the multimeter and distelec gave me back the money.at the same price i bought a brymen BM867S that works perfectly!