digital calipers cheap variety

[Robin teslarParticipant @robinteslar]

Posted by Jon on 17/01/2016 21:54:14:

Its called progress, something the Chinese will eventually copy.
No need on IP66 or IP67 stuff.

Wish I could get my £7 Aldi Chinese calipers not to throw up constant spurious readings.

Indeed the point of my OP. I was amazed at how this cheap caliper could go suddenly wrong and loose its datume without warning. It didnt just wander a little bit, It would go completely wrong. I had to take the best of 3 readings to have some confidence, and move the slide gently. Waste of time.

[VicParticipant @vic]

You don't need to spend a fortune to get a decent brand of digital caliper:

**LINK**

[Nick_GParticipant @nick_g]

Posted by Vic on 18/01/2016 09:04:11:

You don't need to spend a fortune to get a decent brand of digital caliper:

**LINK**

.

Got a pair of those. They are made in China and rebranded with the M&W logo.

They are (well mine are anyway) totally rubbish.! – Within 6 month they started throwing considerably false readings at random. Changed the battery several times to no avail.

Finally took it to pieces and cleaned it which for short time worked. I have no faith in it any more and it now lays unused. But then again it was only 20 odd quid.

I also have a M&W digital height gauge. While it works OK it feels cheap and not a quality product. I don't think IMHO that M&W are the company they once were.

Nick

[Chris Evans 6Participant @chrisevans6]

It would appear that I have been lucky with my cheap caliper. I had a Mitutoto caliper with data output in the very early days when they where around £85 late 80s? This was replaced with another Mitutoyo caliper which also lasted well. I bought my Aldi one on a whim and liked the bigger display so the Mitutoyo was relegated to the drawer and then given to a friend. I also have a SIP 12" caliper which works well but does not see the use of the smaller one.

Next time I see one cheaply I will buy another to see if it is any good, if not maybe buy the branded one again.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Robin teslar on 18/01/2016 07:03:44:

I was amazed at how this cheap caliper could go suddenly wrong and loose its datume without warning. It didnt just wander a little bit, It would go completely wrong.

.

Robin,

I am quoting your observation ^^^, just for emphasis.

Such behaviour is within the very nature of digital devices; [although the problems can to some extent be mitigated by interference suppression and 'error correction' ] … At a practical level; the mechanical design, and physical build-quality are more important than some suppliers might have us believe.

I hope, and expect, that your new/old Mitutoyo will demonstrate this to your satisfaction.

MichaelG.

[Ian S CParticipant @iansc]

miracle, my 200 mm calipers have come back to life, must just have needed the meths to dry out after the clean up, so back to normal.

Ian S C

[Ady1Participant @ady1]

The only problem I've had with cheaper calipers is the battery lasting about 3-6 months

Since they are poundland batteries I shouldn't be surprised, I believe silver oxide are the good ones if you want decent battery life

[KWILParticipant @kwil]

The cheap M&W does not mention accuracy and the others +/- 0.001, you can read a mic better than that and a mechanical vernier is just as useful, if not better and does not give veriable readings!

[Neil WyattModerator @neilwyatt]

Digital scales work using capacitance, so the presence of anything unexpected between read head and scale will cause problems. Cleaning and drying will cure most deviant behaviour.

I think the benefit with the old MT ones is that they detect the error and let you know, they also remember an absolute position. These things are great, but cost.

The new Mitutoyo ones that work when wet may possibly be inductive?

A search of Google patents shows that in 2001 Mitutoyo patented inductive scales that are resistant to coolant…

Neil

[MalcBParticipant @malcb52554]

Posted by Ady1 on 18/01/2016 11:39:39:

The only problem I've had with cheaper calipers is the battery lasting about 3-6 months

Since they are poundland batteries I shouldn't be surprised, I believe silver oxide are the good ones if you want decent battery life

Big problem with some of the Chinese versions is the fact that they use a lot more current both in service and when switched off. This could be helped by taking the battery out each time after use but very inconvenient.

I still get about 2 years life out of my approx 20 yr old Tesa calipers, just hope they keep on going

You may have to just skip the add.

**LINK**

[AjohnwParticipant @ajohnw51620]

One of the problems with digital things is that they usually have an error of +/- 1 of what ever their finest division is as what ever it is measuring may be nearly reaching it. Doesn't matter what it is even digital scales have this feature. The only one that doesn't as far I know are the ones Bwelectronics make. They resolve to more precision than they display. Most things don't 'cause it's good for marketing. Best example is mic's reading to a micron. If only the frames were rigid enough and ratchets etc or fingers consistent enough to do that. Actually people that use mic's a lot are usually aware that the ratchets even on analogue mic's are pretty useless – in the real world for instance more pressure is needed on flat surfaces than on diameters.

Analogue measuring devices can be gauged by eye against the scales, even on vernier scales to a certain extent.

The rest on both types comes down to how accurately they are made and ease of use for the accuracy that is needed. That is one area where I feel callipers fall down and aren't really suitable in many situations for super accurate measurements – not even to the accuracy that their readings suggest let alone the errors.

John

–

[Nick_GParticipant @nick_g]

Posted by Neil Wyatt on 18/01/2016 12:01:12:

Cleaning and drying will cure most deviant behaviour.

.

That's it then. I shall try it.

More baths and showers for me.

Nick

[Michael GilliganParticipant @michaelgilligan61133]

Posted by KWIL on 18/01/2016 11:56:16:

The cheap M&W does not mention accuracy …

.

… but it does claim to be compliant with DIN862 and the 'resolution' is given on the Additional Information tab.

Most interesting is the fact that it can be supplied with a certificate

[Having produced a few of these myself, I would just note that it is likely to be very carefully worded.]

MichaelG.

 

Edited By Michael Gilligan on 18/01/2016 13:55:46

[Robin teslarParticipant @robinteslar]

Posted by MalcB on 18/01/2016 12:34:30:

Posted by Ady1 on 18/01/2016 11:39:39:

The only problem I've had with cheaper calipers is the battery lasting about 3-6 months

Since they are poundland batteries I shouldn't be surprised, I believe silver oxide are the good ones if you want decent battery life

Big problem with some of the Chinese versions is the fact that they use a lot more current both in service and when switched off. This could be helped by taking the battery out each time after use but very inconvenient.

I still get about 2 years life out of my approx 20 yr old Tesa calipers, just hope they keep on going

You may have to just skip the add.

**LINK**

Thanx for that link, fascinating who d'a thought it, the cheapo consumed 8 times as much as the mito when switched OFF

So if your caliper is going to ly in a drawer for months then take the batteries out

[VicParticipant @vic]

Posted by Nick_G on 18/01/2016 13:27:19:

That's it then. I shall try it.

More baths and showers for me.

Nick

Will that be "Pears" or " Wrights coal tar"?

[Author]

Posts