Author Topic: ADCMT 7480T 8.5 digit multimeter (Read 13998 times)

TheSteve · « **on:** January 04, 2018, 05:13:17 am »

Thought everyone might enjoy some details and pictures of the the ADCMT 7480T 8.5 digit multimeter.

ADCMT separated from Advantest in 2003.

The 7480T was made by ADCMT for Advantest, they don't sell it and I've been told to contact Advantest for information. I have not received any reply from Advantest. There are no public docs on the meter, I have only found details on its little brother the 7470 7.5 digit version.

The details I do know:

LTZ1000CH ref - 13K/1K temp set point.
9K ohm hermetic AE branded resistor ref.
Artifact calibration - 9-11 VDC/9-11Kohms.
DCV and 2/4 wire ohms support. 1000 VDC/10 meg ohm top ranges.
Has internal calibration which is recommended to be used every degree C/ 24 hours. A full DCV/resistance internal cal takes 4.5 minutes.
When the meter boots it says 6581T on the display, it also reports 6581T via GPIB. USB is disabled.
Fan airflow only runs over the power supply/digital section.
Front/rear jacks selected electronically(rather useful).

No idea when it was calibrated but it arrived reading within 1 PPM of the last cal value of my 732A - hard to complain about that.

TheSteve · « **Reply #1 on:** January 04, 2018, 05:15:23 am »

pics:

TheSteve · « **Reply #2 on:** January 04, 2018, 05:16:50 am »

TheSteve · « **Reply #3 on:** January 04, 2018, 05:17:51 am »

TheSteve · « **Reply #4 on:** January 04, 2018, 05:19:13 am »

TheSteve · « **Reply #5 on:** January 04, 2018, 05:20:25 am »

TheSteve · « **Reply #6 on:** January 04, 2018, 05:22:06 am »

TheSteve · « **Reply #7 on:** January 04, 2018, 05:23:35 am »

TheSteve · « **Reply #8 on:** January 04, 2018, 05:24:53 am »

TheSteve · « **Reply #9 on:** January 04, 2018, 05:26:43 am »

pics

And docs - I had google translate the 7470(not the 7480) manual which is 98% the same in term of the menus and such. I can find no actual 7480 documents.

Vgkid · « **Reply #10 on:** January 04, 2018, 05:44:34 am »

Thanks for all of those pics , the board in img 2426 with the transistor array in interesting.

Pipelie · « **Reply #11 on:** January 04, 2018, 06:07:21 am »

Thanks for all of those pics.

I saw a ADCMT 7408T a yeas ago on 38Hot , here it is: http://bbs.38hot.net/thread-193743-1-1.html
The seller asking 2.88W RMB for this unit, last time I checked it still there. I have a change to have a look what's inside recently, it appears to be a Simplified version of 6581?

TheSteve · « **Reply #12 on:** January 04, 2018, 06:10:26 am »

Quote from: Pipelie on January 04, 2018, 06:07:21 am

Thanks for all of those pics. I saw a ADCMT 7408T a yeas ago on 38Hot , here it is: http://bbs.38hot.net/thread-193743-1-1.html
The seller asking 2.88W RMB for this unit, last time I checked it still there. I have a change to have a look what's inside recently, it appears to be a Simplified version of 6581?

I believe an updated version of the 6581 is exactly what it is. I have a feeling Advantest has a need for it, possibly for internal testing etc and commissioned ADCMT to make it for them.
It would be really nice to find published specs for the unit.

zhtoor · « **Reply #13 on:** January 04, 2018, 06:58:09 am »

LTZ1000CH rebranded PHILIPS

anybody know of such an arrangement?

-zia

TheSteve · « **Reply #14 on:** January 04, 2018, 07:00:21 am »

Quote from: zhtoor on January 04, 2018, 06:58:09 am

LTZ1000CH rebranded PHILIPS

anybody know of such an arrangement?

-zia

Umm, try again. The ref was made in the Philippines.

Pipelie · « **Reply #15 on:** January 04, 2018, 07:01:09 am »

Quote from: TheSteve on January 04, 2018, 06:10:26 am

Quote from: Pipelie on January 04, 2018, 06:07:21 am
Thanks for all of those pics. I saw a ADCMT 7408T a yeas ago on 38Hot , here it is: http://bbs.38hot.net/thread-193743-1-1.html
The seller asking 2.88W RMB for this unit, last time I checked it still there. I have a change to have a look what's inside recently, it appears to be a Simplified version of 6581?

I believe an updated version of the 6581 is exactly what it is. I have a feeling Advantest has a need for it, possibly for internal testing etc and commissioned ADCMT to make it for them.
It would be really nice to find published specs for the unit.

SPEC in the manual you uploaded, check page 80. hmm, that's the manual of 7470

http://www.adcmt.com/techinfo/product/catalog_ducument/pdf/catalog_Gene_7470.pdf

3roomlab · « **Reply #16 on:** January 04, 2018, 07:02:44 am »

hmmm the manual only states accuracy spec to 7.5 digits. did i miss anything? or it wasnt intended for 8.5D operation? (i assume 8.5D in GPIB?)
and running my eyes over the R7/R4 in pic 2442, is that really a precision 120 ohm in SMD format?

zhtoor · « **Reply #17 on:** January 04, 2018, 07:05:35 am »

Quote from: TheSteve on January 04, 2018, 07:00:21 am

Quote from: zhtoor on January 04, 2018, 06:58:09 am
LTZ1000CH rebranded PHILIPS

anybody know of such an arrangement?

-zia

Umm, try again. The ref was made in the Philippines.

my bad!!!

TheSteve · « **Reply #18 on:** January 04, 2018, 07:15:56 am »

Quote from: 3roomlab on January 04, 2018, 07:02:44 am

hmmm the manual only states accuracy spec to 7.5 digits. did i miss anything? or it wasnt intended for 8.5D operation? (i assume 8.5D in GPIB?)
and running my eyes over the R7/R4 in pic 2442, is that really a precision 120 ohm in SMD format?

Those are the specs for the 7470, not the 7480. The 7470 is limited to 7.5 digits, the 7840 allows 8.5 digits.
That is a 120 ohm SMT resistor, right above the super tiny 13k/1k divider resistor.

Mickle T. · « **Reply #19 on:** January 04, 2018, 07:48:08 am »

Thanks for all of those pics!
Only one question: what is a lower limit of the integration time in this meter (how fast is it)?

Andreas · « **Reply #20 on:** January 04, 2018, 06:29:08 pm »

Hello,

interesting.
Are the blue resistors FLCY from Alpha Electronics?

With best regards

Andreas

branadic · « **Reply #21 on:** January 04, 2018, 06:48:19 pm »

Quote

Are the blue resistors FLCY from Alpha Electronics?

They are networks with 2 resistors, so maybe SLD series? You can see the designations "7K34 XF 10K0", "17K0 XF 19K0" and "..K0 XF 17K0". The last one is not fully visible on none of the pictures.

I also wonder what this magic board with SOT23-3 ic is for.

-branadic-

Mickle T. · « **Reply #22 on:** January 04, 2018, 06:48:46 pm »

Its SLD and SS resistor networks from Alpha Electronics.
I think "..K0 XF 17K0" - is a 10k-17k.

Andreas · « **Reply #23 on:** January 04, 2018, 07:36:42 pm »

Quote from: branadic on January 04, 2018, 06:48:19 pm

I also wonder what this magic board with SOT23-3 ic is for.

Perhaps a multiplexer built with discrete FETs?

with best regards

Andreas

branadic · « **Reply #24 on:** January 04, 2018, 08:13:19 pm »

Quote

I think "..K0 XF 17K0" - is a 10k-17k.

Okay... you seem to have a schematic of this section, can you link it here?

-branadic-


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Author Topic: ADCMT 7480T 8.5 digit multimeter (Read 13998 times)

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