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This HIOKI DM7276-01 has been added to my lab.
It is advertised as a 9ppm/year 7 1/2 digit DC Voltmeter with touch screen a very small footprint and lightweight.
Some specs:
- 100 mV ( ±120.000 00 mV) to 1000 V ( ±1000.000 0 V ), 5 ranges
- High-accuracy model with 1-year 9ppm Accuracy
- Capacitance contact check (using built-in C-monitor)
- Supports global production with built-in variable power supply
- Built-in EXT I/O, LAN, and USB
- Outstanding Long-term stability and Temperature characteristics
- Excellent noise performance approaching an 8-½ digit DMM
- Specifications ideal for everything from R&D to production lines at ¼ the conventional costs
I am just starting using this instrument and the first thing that is noticeable is its very fast warmup time from around 3 min, maybe less.
Stay tuned, first measurements should be interesting.
Anyone here having experience with this instrument?
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A very interesting find !!
How much did it cost?Can you share the documentation that is only available upon registration? "Instruction Manual", "Communication Command Instruction Manual".
I am already myself
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Teardown?))))))))))))))
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In regards to the documentation, here are the direct download links
HIOKI DM7275, DM7276 - datasheet english
Hioki product overview - Test equipment for batteries english
Hioki DM7275, DM7276 - Manual english
Application notes:
Effect of the measurement target output resistance and voltmeter input resistance on measured values
Measurement of the package potential of laminated lithium-ion batteries
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Here I tested the warmup time of the DM7276.
My LTZ1000 reference was warmed up well, so no influence from that.
This little peak shortly before 2 min seems normal for this instrument.
It seems within 2 min this DM7276 is warmed up to get reliable values.
And this is even faster than the Keithley DMM7510.
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In this picture the Hioki DM7276 was hooked up to my LTZ1000A reference over night
Settings:
- 100 NPLC
- Smoothing filter ON with 5 average readings
The nominal value of my LTZ1000 reference is 7.065,90xV
For comparison I had the Keithley DMM7510 running in parallel to the Hioki.
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It is twice as noisy as the 7510...
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It is twice as noisy as the 7510...
The factor is visible from the example data, but AFAIK the DMM7510 is very mixed perfomance when it comes to noise. For the data I have see, it is very good in the 100 mV range and also good with short integration like 1 PLC. However with 100 PLC the performance is not that great and a bit disappointing - at least with a lower applied voltage. With the test at 10 V the references could be a main factor.
Both meters are not really made for ultimate precision at 100 PLC. The main use is more like relatively fast production tests at 10 PLC or 1 PLC, often with a scanner. -
The Hoki meter is a voltmeter only - so no shunt and not current sources for resistance. This allows for a lower price.
Chances are the accurcy specs for the 10 V range are to a large part limited by reference drift. The external temperature regulation for the LTFLU in the DMM7510 has some disadvantage in this respect. The specs are also only estimates about future performance - the actual performance is usually better, but unknown upfront. Some estimates are more conservative than others. -
It's even a DC-only voltmeter, which further simplifies the input stage and eases timing requirements (while the 3458A is often praised here for its precision and linearity, it was really its speed which puts it ahead, more so in '89).
I was even wondering why they bother with a multi-range DC-only voltmeter. Why not make it 10V only, simplifying the input stage even further (making it cheaper or more precise) and selling it as digitizer? Seems they are eyeing the currently hot battery market.
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Do anyone have more experiences to share on this multimeter?
Maybe some teardown pictures?
Anyone know what voltage reference it uses?
Linearity?
With the collapse of the Japanese yen is is getting relatively inexpensive from Japan.
https://store.shopping.yahoo.co.jp/firstfactory/soku-hioki-dm7276-02.html
373K JPY is around 2.7K USD. Some freight etc added of course.
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While Keysight 34470A and keithley DMM7510 had a dramatic price increased in the last few years, this Hioki Voltmeter has been stable.
Since the warranty has expired on my DM7276-01, and if there is any interest, I could open it up and take some pictures from the inside.
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Since the warranty has expired on my DM7276-01, and if there is any interest, I could open it up and take some pictures from the inside.
It is very interesting
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It has an LTZ1000ACH on a separate small board with all SMD components.
First set of pictures
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Second set of pictures
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Last set of pictures
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Back together and still working.
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In this picture the Hioki DM7276 was hooked up to my LTZ1000A reference over night
Settings:
- 100 NPLC
- Smoothing filter ON with 5 average readings
The nominal value of my LTZ1000 reference is 7.065,90xV
For comparison I had the Keithley DMM7510 running in parallel to the Hioki.
Thanks for the tests and teardown. Something seems wrong with Hioki displayed statistics. P-P cannot be less than twice S_n. P_P would be equal to twice S_n if the distribution is purely bimodal, otherwise P_P should be more than twice S_n. -
Here are the inside of a Hioki DM7275, I don't see any different compared against a DM7276, seems identical to me.
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more Hioki DM7275 pictures.
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Thanks for the tests and teardown. Something seems wrong with Hioki displayed statistics. P-P cannot be less than twice S_n. P_P would be equal to twice S_n if the distribution is purely bimodal, otherwise P_P should be more than twice S_n.
This was a quick and dirty setup, definitely not reliable.
Let me do a proper hookup and testing.
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The inconsistancy between the p-p and standard deviation values has nothing to do with the input signal it is a pure math thing. For a given P-P value one gets the largest RMS value / standard deviation with a kind of square wave and this gets 50% of the p-p value. It is only the SD estimator for a small sample size that adds the extra factor of square root of (N/(N-1)) that can make it slightly larger.
The test description indicates more like a longer test. -
Here are the results of 100 measurements with 100 PLC and smoothing filter ON
The source is a stable LTZ1000A
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1.5 hours later and 1394 measurements later
Same setting