SIEMENS B1023 (NORMAMETER MP14) from 1987 - Pictures, Teardown, Impressions

[Cymaphore]

Hi,

today I want to present to you something I tried to get for quite some time. A 35 year old multimeter that was made in Vienna, Austria. I would consider to be one of the best available hand held multimeters of it's time. Even today, many of the specs are far from being outdated.

SIEMENS B1023

developed and manufactured by NORMA Messtechnik GmbH in Vienna, Austria starting at about 1986 until the end of the 1980ies. In Austria it was mostly available as "NORMAMETER MP14".

In the 90ies, NORMA was purchased by LEM, and later on LEM was purchased by FLUKE, as far as I know.

I purchased the unit recently in east germany. It has a couple of calibration and inspection markings on it. It's condition gives away that it probably had seen a lot of action, but it is otherwise fully functional. I first did the teardown-images, the other pictures are done after I gave it some intense cleaning. The buttons and switches now feel almost like new.

For me this devices carries some sentimental value: One of the models from the same series (but directly from NORMA) was the first digital multimeter that I used when I still lived in Vienna. We were not allowed to touch them unless we  learned our way around analog meters and could handle such an expensive device. Also they wanted us to understand the principles in manual ranging and understanding readings before using a comfortable device.

Highlights

User Manual in manualslib

The B1023 is a 20700 count 4 1/2 digits digital multimeter with fast analog bargraph, math functions and a wide variety of optional features, like a data interface that you could use to connect it to your COMMODORE 64. Unfortunately the device I have was not extended with that interface module.

The DMM chipset of these meters are ASICs built by Austrian Mikro Systeme (AMS). Some of the components and ICs are SMD. One very interesting detail about this device: The shielding coveres virtually everything with only very few gaps. There are even multiple layers of shielding in the button-area.

It's display has a phosphorescent-kind backlight. You can "charge it" using any light source. It improves readability even in dim conditions even without actively "charging" it. Generally the viewing angle has some weak spots and is optimized for a more flat usage of the device.

Numeric readings are updated twice per second, the bargraph updates 25 times per second. Autoranging is quite fast at about 1s for voltage and higher resistance readings, and 2-3s for lower resistance readings. It's basic DC accuracy is 0.04% + 2. The bargraph has multimple different scales and can even be centered and "expanded" (zoomed).

Input protection was implemented according to the standards of it's time (DIN 57411-1A VDE 0411-1 from 1980). It seems to be well designed, gaps, extra insulation, even things that look like they have been added for blast protection. The manual provides a lot of details about that.

The meter has a wide variety of "math" functions, you can use them in most measurement ranges and even combine them. This includes relative, min/max, limit function with accustic violation indication, configurable dB. Example: The reference value of REL can be entered manually and you can then make a limit check +/- some value with centered bargraph view.

It is also possible to change the display update rate and reduce display counts and other things.

The leather case also acts as some sort of "protective holster", it's designed to be used in the case and even has a hole for the power switch.

The manual includes a schematic diagram of the device and is very detailed about everything. I wish I had such a manual for todays devices.

There was a huge variety of accessories available, like high voltage and high frequency probes, industrial data interfaces, high temperature probes, current probes, etc., it's listed at the end of the manual. My device came as basic set 2.

According to the manual the device adjustment/calibration values are stored in EEPROM.

Basic functional check

I was surprised to get perfectly precise readings for all functions where I could verify it. The youngest cal sticker on it looks like being at least 20 years old. I tested at ~23°C after >1h of thermal balancing and used the BM789 for direct comparison. DC voltages from nearby sources give mostly readings identical to the BM789, deviating by 0-1 counts.

DC Voltage (AD584JH):

  * REF value: B1023 reading (BM789 READING)
  * 2.5V: 2.499 (BM789: 2.4982)
  * 5V: 5.001 (BM789: 5.0005)
  * 7.5V: 7.500 (BM789: 7.499)
  * 10V: 10.001 (BM789: 10.001)
 
Precision resistors:

  * 100R: 100.05 (BM789: 99.97)
  * 1K: 1.0002K (BM789: 1.0003K)
  * 10K: 9.997K (BM789: 9.997K)
  * 100K: 100.00K (BM789: 100.02K)
 
I checked some nearby diode in reach, the B1023 measured it at 0.4160V while the BM789 gave a reading of 0.4627V. Output voltage in this mode is 2.72V.

It could surprisingly light up all LEDs that I could grab (red, green, yellow, blue, white) and even gave me voltage drop readings for red, green and yellow.

All in all, it seems like the device is fully working and perfectly within spec. Remarkable.

I attached images of the device and the teardown. I did the teardown images first before cleaning it, the other pictures are done afterwards.

Have fun :-)
Martin


Table of brands and variants

Added later on to this post, after several users posted more information. As an attempt to summarize it. I will update it if possible when I discover new things or people post information (links will be disclosed at the bottom of the table).

NORMA	SIEMENS	GOSSEN	GRUNDIG	ENERDIS
NORMAMETER MP11	B1020	MAVO10	DM60	MULTITEST MT11
NORMAMETER MP12	B1021	MAVO20	DM61	MULTITEST MT12
NORMAMETER MP13	B1022	MAVO30	DM62	MULTITEST MT13
NORMAMETER MP14	B1023	MAVO40	DM63	MULTITEST MT14

Last update: 2021-07-26

Data sources: General online research; own device / manual; information / images posted by: Neomys Sapiens, shakalnokturn

Italic: Assumption (confirmation required) for exact match.

NORMA seems to be the OEM and brand used in Austria
SIEMENS sold them in many countries for a longer time (units with green/cyan SIEMENS logo could be found)
GOSSEN probably sold them in germany, other countries unknown, same with GRUNDIG
ENERDIS sold them in France

[Cymaphore]

More pictures, Teardown

[Cymaphore]

Even more pictures

[Cymaphore]

Some pages from the manual including the schematic.

That's it with the pictures for now.

[HighVoltage]

Nice teardown, thanks for sharing.

We had one in the UNI in the end of the 80s and it was a very special meter.
Especially because it had direct temperature readout from a thermocouple (Type K).

I think it was the very first professional digital meter I had in my hands beside the cheap Metex
In those days our day to day meter was a BBC (now Metrawatt) but fully analog.

How much did you pay for this one and what was the new price in those days ?

[Cymaphore]

We had one in the UNI in the end of the 80s and it was a very special meter.
Especially because it had direct temperature readout from a thermocouple (Type K).

I think it was the very first professional digital meter I had in my hands beside the cheap Metex
In those days our day to day meter was a BBC (now Metrawatt) but fully analog.

How much did you pay for this one and what was the new price in those days ?

I found it on eBay. I had notifications for a couple of related terms on for quite a long time. Got it for 89 €. Pure luck, I think.

Actually I don't know how expensive it exactly was originally. My only indication is, that back then our instructor told us that we better not drop it, since it originally cost about as much as his car. But I've never seen his car, so be carefull about that judgement :-)

[Specmaster]

We had one in the UNI in the end of the 80s and it was a very special meter.
Especially because it had direct temperature readout from a thermocouple (Type K).

I think it was the very first professional digital meter I had in my hands beside the cheap Metex
In those days our day to day meter was a BBC (now Metrawatt) but fully analog.

How much did you pay for this one and what was the new price in those days ?

I found it on eBay. I had notifications for a couple of related terms on for quite a long time. Got it for 89 €. Pure luck, I think.

Actually I don't know how expensive it exactly was originally. My only indication is, that back then our instructor told us that we better not drop it, since it originally cost about as much as his car. But I've never seen his car, so be carefull about that judgement :-)

Nice, thanks for sharing this its most unusual to get a schematic these days as well.         

[Neomys Sapiens]

We had one in the UNI in the end of the 80s and it was a very special meter.
Especially because it had direct temperature readout from a thermocouple (Type K).

I think it was the very first professional digital meter I had in my hands beside the cheap Metex
In those days our day to day meter was a BBC (now Metrawatt) but fully analog.

How much did you pay for this one and what was the new price in those days ?

I found it on eBay. I had notifications for a couple of related terms on for quite a long time. Got it for 89 €. Pure luck, I think.

Actually I don't know how expensive it exactly was originally. My only indication is, that back then our instructor told us that we better not drop it, since it originally cost about as much as his car. But I've never seen his car, so be carefull about that judgement :-)

As far as I can remember, the original price was somewhere around 1400.-DM.

As discussed in the 'show your multimeter' thread, another of it's guises was the Gossen MAVO40.
I am jealous now, as I have only the MAVO30, aka B1022, which is lacking the ''Time' function.
Nevertheless, those are premium quality instruments and the people at Gossen and Norma definitely knew a lot more about instrument design and electrical measurements than most of those who churn out todays 'unstruments' with a 2 year product cosmetic cycle and a large 'Catx' label as their main safety element. On measurement-intensive turnouts, I  use to take it along with a Multizet A1000 as an analogue counterpart.

My thanks for telling about the 'backlight'. I never stumbled across this fact.

[Cymaphore]

As far as I can remember, the original price was somewhere around 1400.-DM.

Thanks for the information. It's a bit difficult to find historic catalogue prices for these devices.

By very quick online research based on inflation, that are about 1200€ in todays money. So the guy either had a seasoned second hand car, or it was just a nice figure of speech to tell us about the value of these things.

As discussed in the 'show your multimeter' thread, another of it's guises was the Gossen MAVO40.
I am jealous now, as I have only the MAVO30, aka B1022, which is lacking the ''Time' function.
Nevertheless, those are premium quality instruments and the people at Gossen and Norma definitely knew a lot more about instrument design and electrical measurements than most of those who churn out todays 'unstruments' with a 2 year product cosmetic cycle and a large 'Catx' label as their main safety element. On measurement-intensive turnouts, I  use to take it along with a Multizet A1000 as an analogue counterpart.

Thanks for pointing out that nice thread :-) ... Just out of interest, does your MAVO30 have the same kind of NORMA production label inside? Some white sticker with "mp13/07" and what looks like the serial number of the PCB in the second line.

I could find out, that NORMA MP11 to MP14 was also sold as SIEMENS B1020 to B1023, GRUNDIG DM60 to DM 63 and GOSSEN MAVO10 to MAVO40. But I'm not entirely confident, information is sparse, but your posting seems to confirm that assumption for the most part.

My thanks for telling about the 'backlight'. I never stumbled across this fact.

We discovered it one day in winter when we switched off the lights and a couple of green ghosts appeared on the lab benches :-) ... It's only mentioned in a half sentence in the manual.

[HighVoltage]

As far as I can remember, the original price was somewhere around 1400.-DM.

This price does make sense, I remember it was very expensive and out of reach as a student at the time.
In perspective, this 1400.-DM was about 3 times what I paid monthly for my apartment in Hamburg.

[shakalnokturn]

Thanks for the teardown.
I own a meter that seems to be a rebrand of yours under the name of Enerdis MT14, bought used for about 85€ shipped.
I haven't checked if it is a true RMS model as yours seems to be.
The French edition of the user manual doesn't have the schematic.

[Neomys Sapiens]

The French edition of the user manual doesn't have the schematic.

Jagottseidank! Dr' Erbfeind scho wieder!

[Cymaphore]

Thanks for the teardown.
I own a meter that seems to be a rebrand of yours under the name of Enerdis MT14, bought used for about 85€ shipped.
I haven't checked if it is a true RMS model as yours seems to be.
The French edition of the user manual doesn't have the schematic.

Thank you for the information! I just updated my original post to include a brand table at the bottom based on what I could find out so far, maybe interesting for someone.

Your device looks like brand new, it must have been sitting in storage unused, wow. Based on the buttons and the manual headline, it's a branded MP14. True RMS is not present on my unit as well, they added it in the successor products (where they also replaced the leather holster/case by a fluke-style soft silicone holster). [Update: I was wrong about it, it is TRMS, see here]

If you ever get the chance to open the back cover, I would love to see some pictures of the inside, the stickers on the PCB could provide more clues about the history of this line of devices. Maybe you got a "mp14/07" label with a serial number on it as well, seemingly not all units have it (or it got lost in some of them) based on the few pictures found online.

I'll try to make a high quality scan of the schematic next time I have access to a decent scanner.

[shakalnokturn]

Sure I'll take a few shots of the insides soon.
It is in great condition, hardly looks as if it has ever been switched on.
I bought a nice Topward dual 60V-3A lab supply from the same seller, to my surprise it came in the original box with polystyrene and crocodile leads.
I just checked the seller still has the MT 10, MT 11, MT 13 all in great condition if anyone out here is tempted ?

[Cymaphore]

Sure I'll take a few shots of the insides soon.
It is in great condition, hardly looks as if it has ever been switched on.
I bought a nice Topward dual 60V-3A lab supply from the same seller, to my surprise it came in the original box with polystyrene and crocodile leads.
I just checked the seller still has the MT 10, MT 11, MT 13 all in great condition if anyone out here is tempted ?

As mentioned via PM, I would be quite interested. Your device from ENERDIS (since 1998 part of Chauvin Arnoux) look like it's been sitting brand new in stock for 30 years. There is virtually no information that can be found online about them, so they seemingly are an absolute rarity. But if anyone else is interested, I would step back, because I already have one device and don't want to be greedy about it :-) ... But maybe the seller has other related things of interest to me.

[Cymaphore]

After careful examination of the images of the seller, it indeed looks like the ENERDIS MT devices he offers are actually unused stock items. It looks like the leads are still in original packaging, the plastic doesn't even look wrinkled. No scratch, no dust, no dirt visible on the devices at all. And that for sub 100€. Wow.

I think we are looking at the last remains of a failed attempt to enter the french market. It seems likely, that only a few of these ENERDIS MT have even been produced, considering there is absolutely no information about them anywhere to be found at all.

It's not entirely unlikely that you are the sole owner of the single still existing ENERDIS MT14 on the planet, or at least one of very few. Congratulations :-)

[Neomys Sapiens]

Thanks for the teardown.
I own a meter that seems to be a rebrand of yours under the name of Enerdis MT14, bought used for about 85€ shipped.
I haven't checked if it is a true RMS model as yours seems to be.
The French edition of the user manual doesn't have the schematic.

Thank you for the information! I just updated my original post to include a brand table at the bottom based on what I could find out so far, maybe interesting for someone.

Your device looks like brand new, it must have been sitting in storage unused, wow. Based on the buttons and the manual headline, it's a branded MP14. True RMS is not present on my unit as well, they added it in the successor products (where they also replaced the leather holster/case by a fluke-style soft silicone holster).

If you ever get the chance to open the back cover, I would love to see some pictures of the inside, the stickers on the PCB could provide more clues about the history of this line of devices. Maybe you got a "mp14/07" label with a serial number on it as well, seemingly not all units have it (or it got lost in some of them) based on the few pictures found online.

I'll try to make a high quality scan of the schematic next time I have access to a decent scanner.

According to my information (old Siemens catalogue and Manual) as well from the brochure when I was offered it in the late 80s, at least all 1022/1023 are TRMS measuring, whether marked so or not.
And your teardown pics support this! See my edited picture. One of your pictures show it from above too.

@shakalnokturn: why do you think that yours is not, as it is explicitly marked so?

[Cymaphore]

According to my information (old Siemens catalogue and Manual) as well from the brochure when I was offered it in the late 80s, at least all 1022/1023 are TRMS measuring, whether marked so or not.
And your teardown pics support this! See my edited picture. One of your pictures show it from above too.

@shakalnokturn: why do you think that yours is not, as it is explicitly marked so?

You are absolutely right, that component is in fact labeled "AD636JH 8825(delta)". So that's why it takes a bit more time to provide the first numeric voltage reading in ACV :-)

So it is True-RMS after all! Thanks for correcting me.

[shakalnokturn]

@shakalnokturn: why do you think that yours is not, as it is explicitly marked so?

I'm probably confused, will just have to open the meter to check.
I seem to remember reading something somewhere (or maybe just photos) that mentioned a difference between the meters marked RMS and those marked TRMS.

Edit:
Likely this page got me confused: https://sigrok.org/wiki/Norma_DM950

[TimFox]

Hewlett-Packard was careful on their AC voltmeters that were not “true rms” to print “average responding” on the meter face.  Technically, that meant measuring the average of the absolute value, with the meter calibrated to show the rms value of a sine wave with that average value.

[shakalnokturn]

Here's a peep in my MT14, pretty much the same confirms it is true RMS too. No sticker though.

[Cymaphore]

I just created a video about the meter demonstrating some of the functions and abilities, also doing the "fast autranging" check in ohms with BM789:

Here's a peep in my MT14, pretty much the same confirms it is true RMS too. No sticker though.

Thank you! The PCB branding between the A and mA jacks has identical markings and I could not find any differently eqipped parts at the first look. The only real difference seems to be the covering of some of the components.

[MarcX]

Grundig numbering scheme doesn‘t match in first Post.

Models are
DM60 (MP11)
DM62 (MP12)
DM64 (MP13)

MP14 was also sold as Grundig but if i am remembering correctly it was labeled with DM68 instead of DM66.

MAVO numbering scheme is correct.

[goaty]

Anyone has calibration procedure or EEProm layout ?

[reheld]

Cymaphore is sending me his manuals for digitizing, if someone also wants to get his manuals digitized/likes to share with us,  please contact me. Maybe we are able to collect all variants including the lower end Models like MP11. I‘ve seen there are multiple different hardware revisions and corresponding manuals/schematics. For example the  schematic in Cymaphores english manual differs from the schematic of the published german B1023 Manual.

I will also publish the manual of my Normameter MP12.