Metrix MX56C / BK Precision 5390 Multimeter Teardown

[Robomeds]

Recently I picked up a BK Precision 5390 to complement my 5360.  Thanks to one of Dave’s videos I discovered that the 53_0 BK meters were Metrix MX series models made in France no less.  The 5360 is the MX53C and the 5390 is the MX56C.  The less one is a 50,000 count, .1%+2counts meter while the 5390 steps up to 50,000 count at .025% +2 counts.  Quite impressive specs. 
The meters are also IP677 rated thus meting the same 1m submersion standard the Fluke 27 claims.  I doubt they are as rugged as the 27 but if you like to swim with your meter, well these claim they can go. 

I’m going to skip over much of the usage discussion.  Overall I’ve found these to be nice to use meters.  The continuity tester is quick but scratchy.  The auto range is plenty quick.  They have a touch hold function similar to a Fluke as well as conventional hold features. 
For me, the build and design is what makes this meter more interesting.  Forgive me but I think it’s a bit like the few older French cars I’ve been exposed to.  Sometimes you wonder why they did something so much different than the rest.  Other times you wish the rest would copy this feature or that. 

Prior to opening this meter I have a few comments.  The case feels very solid.  No flex at all.  The tilting stand is small and cheap feeling.  It doesn’t lift the meter up that much.  The interesting thing is the stand is meant to be detached and used as a tool to open the front mounted battery door.  As part of the ASYC II safety stuff the battery door is actually the front panel of the meter.  Thus you must disconnect the leads in order to access the battery.  The battery cover snaps in place on the sides and the stand is used to unsnap the case. 

Before we go deeper, the control knob is easy to grasp but feels a bit metallic and certainly sounds metallic.  The 5390 didn’t come with original leads but my 5360 came with leads that would seem reasonable for a $50 meter.  I don’t think these were in that price range when new. 

So pulling the front panel off we see a water proof secondary cover over the batteries and fuses.  The walls of the battery/fuse compartment act as blast walls for the fuses.  The fuses themselves are ceramic, 600V units rated to 1.5kA and 30kA interrupt current (.63A and 10A).  Needless to say they don’t look impressive next to those in a Fluke 87.  It’s interesting as this meter looks like the safety features aren’t as impressive as the Fluke 87 but things like the IP rating suggest this was meant to be a rugged meter, not just a battery operated bench meter. 

Anyway, let’s start opening things up. 

The button panel is unsnapped from the side.  The membrane of buttons lifts out of the front of the meter.  The bottom removal is VERY interesting.  You press in on two tabs molded into the upper housing.  That allows you to unsnap the lower housing.  There is a large, white gasket between the two as well as some decent wall overlap. 

Once inside we see the back of the main PCB.  Note the gold colored plating where the terminals are bolted to the PCB.  Very clean construction.  The RF shield is soldered in place and includes a foil patch over some adjustment caps.  To remove this PCB we again deal with snaps!  The bottom of the board is held in by the nuts but the top is held in place by a snap feature integrated into the screen surround which snaps into the upper housing.  Once you know about these snaps the meter is rather easy to open. 

This is a good place to cut this off and continue in a new post. 

[Robomeds]

The rest of the disassembly is a few snaps and disconnecting the header between the display and main boards.  The construction quality seems first class to my semi-trained eye.  Note the black foam gasket under the area where the battery would sit.  I assume this is meant to further prevent dirt from migrating in the meter. 

Looking at the safety bits, I see no cut outs in the board.  I assume they maintain decent spacing.  The blast shielding for the fuses is integrated in the battery compartment.  It’s worth noting that the meter will not operate if the high current fuse is blown.  It will just say Fuse 2 on the screen.  If Fuse 1 is blown it will say Fuse 1 when in the uA/mA range.  There is no input jack warning. 

On the high voltage side we have a PTC and 4 MOVs.  I believe I saw a family of diodes under the RF shielding on the back of the board.  Overall it looks better than the other meters I’ve been showing recently. 

The current shunt is also not like any other I've seen.  No idea why they used a sheet metal 'M' rather than the normal wire.  Perhaps they just wanted to have M for Metrix in the meter.

Other features worth noting are the adjuster caps including C14 and the resistor hybrid next to it.  The selector knob consists of a blue frame and the white rotor with contacts that wipe the board.  The blue frame has pins which limit travel.  One of the two ITT-Metrix chips can be seen.

Note the IR couple in the black gasket area.  I don't quite know how Metrix expect that to be used given that you must remove the battery cover to access the IR interface. 

[Robomeds]

Moving further up we see the main Metrix DMM5 chip.  Ah, the famous DMM5 which I had never heard of earlier this evening.


There is an interesting Analog Devices regulator near the main chip, an AD636JH 9625.


Edited to experiment with pictures.

[Robomeds]

Next we have the screen and button interface board.  The buttons are membrane type.  I checked on the 5360 and like many meters it has unused "buttons" under the panel.  The 5390 has a full complement.  Anyway, a few of the contacts are interesting in that 3 rather than 2 pads exist under the buttons.  There is basically nothing but the button pads and traces on the screen side of the board.  The so-so green LEDs are also on that side.  The back size uses an NEC asyc to run the screen. 

[Amarbir[Lynx-India]]

Well,
       I Love These Meters ,Very Solid And If There is a Fight In The Lab you Know what i Am Talking About ;-)

[Wytnucls]

Interesting meter.
Some corrections:
There is no MOV, R2 is a Gas Discharge Tube (Spark Gap) fulfilling the same function.
AD636 is not a regulator but the True RMS to DC converter (1% max error version).
The IR diodes are probably only used for software calibration.

[Robomeds]

R2 is a PTC, the print was hard to read but it said so on the side.  The MOVs are RV1-4.
If the IR diodes are only used for calibration I don't understand the RS232 output of this meter.  When you press the print button the meter outputs vs RS232.  Those LEDs are the only such interface I noticed.  Thanks for the info on the TRMS converter.  The 5360 didn't have that particular part.  Then again its accuracy wasn't as high either.

[Wytnucls]

Here is the manual: http://www.chauvin-arnoux.us/pdfs_aemc/user-manuals/MX56_EN.pdf
It does have a RS232 print function, with the optional adapter:
http://www.testitnow.co.uk/media/files/test_equipment_manuals/Metrix-Chauvin%20Arnoux/Metrix%20MX56.pdf

[zaoka]

It has been sold under AEMC name as well. Did not know they are made in France.

I remember long time ago AEMC offered there meters at huge discount. I have seen them under ITT name as well.

[Robomeds]

Who is ITT?  Clearly they are more than an Extech since their name is on the main IC. 

[Amarbir[Lynx-India]]

Robomeds ,
      I Have a suggestion When You Make a Review Like This .I Can Let You Know If you Have No Issues .

[free_electron]

Jep. These are originally ITT machines. Itt intermetall doesnt exist anymore. They were a large ic maker from germany. The ITT concern made tv's , vcrs and other stuff. They were large in automotive as well. Many upscale german cars from the 80's and 90's had itt chips in em.

Itt invented the digital television. Digit2000 system. The digitized the viadeo and audio in the tuner and the rest was a collection of 40 pin dip ic's on a bus. There was a pal decoder, secsm decoder, teletext chip, nicam chip, main cpu, deflection processor, rgb processor and many more.

Depending on what features you wanted tou just plonked chips on the bus. The software did the rest.
The silicon division was acquired by Nokia in the mid 90's and later merged with the Micronas group. The digit 2000 platform lived on for a while in some micronas chips. Up till a few years ago there was a combo chip that basically had the whole audio/video digital processor in 1 chip. These were used frequently in pc tv tuner cards. When analog tv disappeared micronas folded that business. Micronas still makes specialised automotive chips for sensors. They even have special cpu's(based on 6502 architecture!). They still use the silicon plant in Freiburg Germany that was the ITT intermetall plant.

ITT had a test and measurement division as well. This meter is one of them. They are very good designs. At the time of their relase Fluke was unknown i europe and these were the rolls-royce of the meters. chauvin-arnoux was a large french distributor of test euwipment and components and they rebadged them.

All those components you see in there (melf resistors, caps, trimpots) are made by ITT. they did everything. Even the lcd glass.
ITT knitter still makes switches today. So does ITT cannon.
The rest is gone, spun off.

At their heyday they rivaled Philips in terms of making every single component from wire to resistor to led to chip in house.

ITT still exists and does many things but no longer semiconductors and consumer goods.
ITT is short for internstional telephone and telegraph company. They are a very old company. Pre world war 1 i believe.

Actually the ITT university and career decelopment centers are owned by them.
They still have a large protfolio of components.

[Amarbir[Lynx-India]]

Jep. These are originally ITT machines. Itt intermetall doesnt exist anymore. They were a large ic maker from germany. The ITT concern made tv's , vcrs and other stuff. They were large in automotive as well. Many upscale german cars from the 80's and 90's had itt chips in em.

Itt invented the digital television. Digit2000 system. The digitized the viadeo and audio in the tuner and the rest was a collection of 40 pin dip ic's on a bus. There was a pal decoder, secsm decoder, teletext chip, nicam chip, main cpu, deflection processor, rgb processor and many more.

Depending on what features you wanted tou just plonked chips on the bus. The software did the rest.
The silicon division was acquired by Nokia in the mid 90's and later merged with the Micronas group. The digit 2000 platform lived on for a while in some micronas chips. Up till a few years ago there was a combo chip that basically had the whole audio/video digital processor in 1 chip. These were used frequently in pc tv tuner cards. When analog tv disappeared micronas folded that business. Micronas still makes specialised automotive chips for sensors. They even have special cpu's(based on 6502 architecture!). They still use the silicon plant in Freiburg Germany that was the ITT intermetall plant.

ITT had a test and measurement division as well. This meter is one of them. They are very good designs. At the time of their relase Fluke was unknown i europe and these were the rolls-royce of the meters. chauvin-arnoux was a large french distributor of test euwipment and components and they rebadged them.

All those components you see in there (melf resistors, caps, trimpots) are made by ITT. they did everything. Even the lcd glass.
ITT knitter still makes switches today. So does ITT cannon.
The rest is gone, spun off.

At their heyday they rivaled Philips in terms of making every single component from wire to resistor to led to chip in house.

ITT still exists and does many things but no longer semiconductors and consumer goods.
ITT is short for internstional telephone and telegraph company. They are a very old company. Pre world war 1 i believe.

Actually the ITT university and career decelopment centers are owned by them.
They still have a large protfolio of components.

Boss ,
      Beautiful Info .I still did not get one thing ? .Someone was making for chauvin or they were making it using stuff from itt ? .As far as i know BK precision ,AEMC And Metrix have these type of multimeters .BTW i still see some little different once on chauvin website  .They made some awesome jaw dropping Analogue multimeters also 

[free_electron]

I just looked up itt on wikipedia. You need to read that. Those guys are huge , but virtually unknown to the masses.
They even bought farnsworths tv business! They invented digital phone exchanges, pulse code modulation, fiber optics and all kinds of other stuff.

http://en.wikipedia.org/wiki/ITT_Corporation

I knew the intermetall group well as i was a trainee in 1989 and the two successive years at Nokia in Finland (when i was in highschool i won a contest sponsored by Rotary. last-year students(18 years) from many schools had to make a practical project. I had made a satellite receiver based on a tuner from nokia salcomp(the metal can) , a 8051 ah basic and a rgb decoder TDA4550 i believe.. It could point the antenna and had an infrared remote control. I won first prize, which was 2 months as an intern during summer holidays in a company of you choice. I picked Nokia in finland. I spent three summers there. I was in Kemijarvi , just above the polar circle. 24 hour daylight). As an 18 year old i was tinkering with 40Ghz spectrum analyzers... Building digital satellite receivers (D2MAC )...

 When they just began designing with the digit2000 chips. A few years later Nokia acquired that group and fused it with their micronas group. They are today still in freiburg, germany where intermetall began.

[free_electron]

Chauvin rebadged the itt meters. Chauvin doesnt make anything. They buy in bulk , specify color and slap their name on it.

ITT metrix was rhe test and measurment division of ITT. That group was in france. The chips came from ITT intermetall in Freiburg, Germany. All other components you see came from various ITT divisions all over the world.  My estimate is that 95% of the parts in that meter were made by ITT divisions. Those guys did everything.

[Amarbir[Lynx-India]]

I just looked up itt on wikipedia. You need to read that. Those guys are huge , but virtually unknown to the masses.
They even bought farnsworths tv business! They invented digital phone exchanges, pulse code modulation, fiber optics and all kinds of other stuff.

http://en.wikipedia.org/wiki/ITT_Corporation

I knew the intermetall group well as i was a trainee in 1989 and the two successive years at Nokia in Finland (when i was in highschool i won a contest sponsored by Rotary. last-year students(18 years) from many schools had to make a practical project. I had made a satellite receiver based on a tuner from nokia salcomp(the metal can) , a 8051 ah basic and a rgb decoder TDA4550 i believe.. It could point the antenna and had an infrared remote control. I won first prize, which was 2 months as an intern during summer holidays in a company of you choice. I picked Nokia in finland. I spent three summers there. I was in Kemijarvi , just above the polar circle. 24 hour daylight). As an 18 year old i was tinkering with 40Ghz spectrum analyzers... Building digital satellite receivers (D2MAC )...

 When they just began designing with the digit2000 chips. A few years later Nokia acquired that group and fused it with their micronas group. They are today still in freiburg, germany where intermetall began.

Heavens Goodness ,
            I Searched For ITT Multimeters and Here You Go .Bloody Hell Never New This .BTW You Know i Am In such a Country Where Doing Business And Importing Is a Big Big Issue .Very Often i Do Buy Old ITT Akka Chauvin Akka Metrix Aka BK Precision Multimeters And They are still spot on  " Checked " With Voltage Standard DMM Check Plus  .The Last One i Had I Sold That .These Things Are Heavy And Built Like Tanks .Thats Why i Was Saying On The Lighter Side That If You Do Indeed Have a Fight In The Lab You Know What Instrument You Can Use there Lol  . 

[free_electron]

Correction . I said itt knitter , but it is ITT Schadow that made switches together with ITT cannon.
They are now c&k and alps.

Knitter is a different company that still exists and ITT cannon still makes many connectors.
A well known switch was the Digitast. A spring loaded pushbutton that had a unique property : it does not have contact bounce.

You need to read the history of ITT. They basicaly were the grandfather of Alcatel , the system 12 phone exchange, that today is srill in production by alcatel. BTM is Bell Telephone Manufacturing in antwerp Belgium...

They owned Avis , the hartford group , hotle chains.
They did dirty work topplling and installing dictators, traded in arms, got sued by the government.
Sheesh what a company ...

[Robomeds]

Robomeds ,
      I Have a suggestion When You Make a Review Like This .I Can Let You Know If you Have No Issues .

Sure, my feelings aren't to fragile

[Amarbir[Lynx-India]]

Mods ,Please Delete This Post

[Amarbir[Lynx-India]]

Robomeds ,
      I Have a suggestion When You Make a Review Like This .I Can Let You Know If you Have No Issues .


Sure, my feelings aren't to fragile

Thanks ,
 Many Contributors On Forums Feel Not Quite Easy When Someone Does That ,Thanks Here You Go .

"I Feel That When i Followed Your Article ,I Had To Use More then brain power to go with the flow  .This is what i do when i do something like this i mean the review .I attach the pictures to the thread and then i get the location of the images and i embed then one by one under the text of the stuff i write .Something like this -> http://www.lynxchandigarh.com/scripts/betaforums/showthread.php?t=2326 .You Will See I Have The Pictures Attached ,Thats All i loved the article though

[Robomeds]

Amarbir,
I understand what you mean about trying to get the pictures and text inline.  Is there a way to do that using this forum to host the images?  In your link I only see the image links at the bottom of the post.  I did see that you changed the image names. 
Thanks,

[Amarbir[Lynx-India]]

Amarbir,
I understand what you mean about trying to get the pictures and text inline.  Is there a way to do that using this forum to host the images?  In your link I only see the image links at the bottom of the post.  I did see that you changed the image names. 
Thanks,

No ,
      I Can See The Files In Post Also "Might Be You Need To Register " ,But My Intention Is not To Force You To Register And See File ,But To Explain You How Its Done  .You Just Try That And Hopefully you will Have a Crystal Clear Idea .I Am 100% Positive It Can Be Implemented And It Will Work Here  .Let Me Try The Same In This Post Only

   All The Stuff You Wanna Put Across To Us In The Forums Goes Here

[Amarbir[Lynx-India]]

Sir ,
      Check This Post Up Now .You Will See I Attached The File First Then i Saved The Post Then i Edited In Another Tab And Took Direct Links Of The Pictures i Attached From Older Tab And Embedded Them In The Post  .

[Robomeds]

OK, I see what you did and was able to get it to work in preview.  Now I have a style question.  If I put the pictures in line will they shrink in size?  In the preview the picture was full size in the text.  That might be a problem for people with a slower connection or smaller screen.  Alternatively I can put a thumbnail in line so you can see which image I'm talking about but if you want to see it in detail you have to click the link at the bottom of the post. 

Thoughts?

[Amarbir[Lynx-India]]

OK, I see what you did and was able to get it to work in preview.  Now I have a style question.  If I put the pictures in line will they shrink in size?  In the preview the picture was full size in the text.  That might be a problem for people with a slower connection or smaller screen.  Alternatively I can put a thumbnail in line so you can see which image I'm talking about but if you want to see it in detail you have to click the link at the bottom of the post. 

Thoughts?

Robomeds ,
 Please Do The Same For One Image And Let Me See How That Goes .I can only advise you after i see that  .