Author Topic: UNI-T UT81B Oscilloscope  (Read 4895 times)

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Offline cs.dk

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UNI-T UT81B Oscilloscope
« on: December 24, 2010, 11:43:58 am »
Hi, new in here, and I have a question.
(Sorry for my english, i'm from Denmark)

I'm looking for an oscilloscope for automotive use. And i've been looking at Uni-T UT81B, which is very fair priced. Any clues about it?
I know it's not a high-end thing, but i really don't think i need more than the 8 MHz.

The things i will need to measure.
Topdeadcenter (rpm-signal), ABS-sensors, and other sensors on the vehicle for fault-finding. The sensors will feed out a sinewave, or a squarewave. But at really low frequency? (Ie. Topdeadcentre @ 3000 rpm would not be much, or am I wrong?)

The Uni-T seems to be better build that the DSO-Nano.
Hope that someone can push me in the right direction. I have been looking at Instek 1000A-series, but as my first oscilloscope, i guess it will be overkill - I can allways upgrade, if i find a oscilloscope usefull.

Thanks in advance
 

Offline saturation

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Re: UNI-T UT81B Oscilloscope
« Reply #1 on: December 24, 2010, 12:50:45 pm »
Have you looked at the Velleman HPS 40?  Its on liquidation sale in many places and it has a following for automotive use.
Best Wishes,

 Saturation
 

Offline cs.dk

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Re: UNI-T UT81B Oscilloscope
« Reply #2 on: December 24, 2010, 12:55:04 pm »
Thanks,
The Velleman looks great to, and it is still very fair priced imo. I can get one from Ebay Germany for ~€200.

Am i right about the frequencies i will need to measure, never will reach the scopes limits?
EDIT: Sure it would not push the scope.. Ie. TDC @ 3000 rpm.. 3000/60=50 Hz. Am i right?
« Last Edit: December 24, 2010, 12:58:45 pm by cs.dk »
 

Offline Chasm

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Re: UNI-T UT81B Oscilloscope
« Reply #3 on: December 24, 2010, 02:21:11 pm »
That is correct, but there is also the possibility that cars use a different encoding scheme. IIRC there were some attempts to change them over the time to make tacho hacks more complicated.

Don't forget that virtually all modern cars use the CAN Bus to connect the various systems. But then CAN is not too fast either.

I would think hard if I really need a hand held oscilloscope.
Their memory depth is tiny unless you buy a high end version. Modern bench DSO have a really small depth and also much more bang for almost the same price.
 

Offline cs.dk

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Re: UNI-T UT81B Oscilloscope
« Reply #4 on: December 24, 2010, 02:35:26 pm »
Thanks,
I won't need CAN-bus, i don't even know how to read/understand the signals. It is primary for older cars, from mid 1990's to ~2000

I think the handheld could be good for troubleshooting. Many sensors sort of disconnect at a given temperature. I know some put them i the oven, and measure resistance, while they are heating up, to see if something is wrong.
If i (a helper) drive, and i watch the scope, i guess i would be able to see the traces of a bad sensor, while the engine cuts out at a certain temperatur.?
 

Offline saturation

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Re: UNI-T UT81B Oscilloscope
« Reply #5 on: January 03, 2011, 09:26:32 pm »
You can download self-tutorials on various waveforms found in modern automobile electronics.  They are most, if not all, far below 10kHz.
« Last Edit: January 04, 2011, 11:31:11 pm by saturation »
Best Wishes,

 Saturation
 


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