Being required to get a different meter when a reading which you are peaking goes above 1 mA doesn't make sense.
Square wave generator is useful for checking different speakers and buzzers. I'm surprised nobody pointed it out.
yes, but isn't the chipset/hardware difference only that "square wave output" feature on AN8008 (ZT109)? and everything else is exactly the same? I mean (AN8002 + EEPROM hack to 9999 counts) is equal to (AN8008 - digital square wave feature) or there is real difference in accuracy? (BTW, on first glance even both PCBs of AN8008 and AN8002 looks very very similar).
And ... what the hell is this? I never saw that on a meter before.
You can't get a 9999 reading of AC voltage with the DTM0660 chipset. Around 8500 seems to be the limit, depening of the crest factor.
The datasheet says battery test for 9V and 1.5V. I guess 40mA load for 1.5V and 24mA for 9V.
The datasheet says battery test for 9V and 1.5V. I guess 40mA load for 1.5V and 24mA for 9V.
More useful than a square wave output!
(Now I need one of those as well. )
PS: Do you think I should send one to Batteroo for their test lab?
I just wonder where do you install the fuse as suggested:
As somewhat referred to previously, the AN8008 is a poor meter to use between 1 - 100 mA. I just completed my detailed accuracy verification of the lower current readings. For an approximately 1 mA current reading I had the choice of 989.8 uA (1.01% low due to the 100.561 meter insertion resistance) or 1.0 mA. Yes, that's two digits, 10% error represented by the least significant digit. That's the best resolution possible just above 1 mA. The -1% uA error continued down to around 200 uA. When the reading was corrected for the added resistance, the uA accuracy was typically below 0.1%.
The DC voltage reading accuracy was typically 0.06% The resistance reading accuracy was typically below 0.3%. Most of my resistors used for accuracy verification were rated at 0.01% accuracy.
More tests tomorrow.
Square wave generator is useful for checking different speakers and buzzers. I'm surprised nobody pointed it out.
Square wave generator is useful for checking different speakers and buzzers. I'm surprised nobody pointed it out.
Sadly not as useful as you might think...
As I mentioned earlier, the square wave comes from quite a high source impedance (about 2k). So by the time you've fed that into an 8 ohm loudspeaker, there's hardly any voltage there. I tried a very sensitive 15 ohm speaker, and you have to hold it to your ear to hear anything from it.
However, it does work on piezo sounders
P.S. It's funny to see people here discussing a thread on kazus.ru. But yeah, their discussion seems to be the most comprehensive one on that matter. I can try to translate something for you if google fails.
It's just too bad for the current...
If this meter is lying around with its false ratings and someone picks it up to use it where they need the real protection because they see the marks, it could kill them or injure them severely.
Place a 1 ohm resistor across a Pomona 1330-2...
I finally got inside of the meter since the AC current measurements don't seem very stable.
QuoteI finally got inside of the meter since the AC current measurements don't seem very stable.
While the two digit ammeter for 1 - 10 mA DC readings might have limited value, it is of no use for AC readings in that range.
While I had reasonable accuracy on the AC uA readings from 10 to 1000 uA, things fell apart when I tried to read 1000 uA as 1 mA AC. The AN8008 showed zero mA for that measurement. My next test measurement was at 3.3 mA. The AN8008 generally stayed at a reading of zero with an occasional jump up only to soon return to zero.
My next step is at 10 mA. By then I had a steady reading which was 8% low. At 30 mA the meter became useful with a reading which was only 1% low. By 75 mA and above the meter's surprising accuracy returned with the accuracy typically below 0.2%.
In mA, mine met the 1.5% spec. The worst error was at 5mA, where I got 4%, but of course, 1 count is 2% at 5mA. Factor in the "3 counts" part of the specification, and 5.2 is indeed OK for 5.0mA. Elsewhere, it was comfortably within 1%.
Personally, I would have preferred it if they'd not bothered with the square wave output, and used the switch position for mA, with a different shunt.
As I mentioned earlier, the square wave comes from quite a high source impedance (about 2k). So by the time you've fed that into an 8 ohm loudspeaker, there's hardly any voltage there. I tried a very sensitive 15 ohm speaker, and you have to hold it to your ear to hear anything from it.
Noob question: I seem to recall reading somewhere that square waves are bad for speakers because the flat parts look like DC, and DC ruins speakers.
Edit1: Reading the small print, that meter needs a weird 12V battery.
Edit1: Reading the small print, that meter needs a weird 12V battery.
I have a similar unit, it uses a 12V battery, same used in many car remotes. Wouldn't call this an issue, but battery costs like half of DMM. I replace it every two-three years or so. It's only 2000 counts, but this is good-enough for most my purposes.
It's just to bad for the current, which blows my mind because the voltage ranges are fine.
I was just wondering, wouldn't be an idea to develop a small daughter board to provide the correct input protection and maybe some extra extra tweaks to get a better current range?
QuoteI finally got inside of the meter since the AC current measurements don't seem very stable.
While the two digit ammeter for 1 - 10 mA DC readings might have limited value, it is of no use for AC readings in that range.
While I had reasonable accuracy on the AC uA readings from 10 to 1000 uA, things fell apart when I tried to read 1000 uA as 1 mA AC. The AN8008 showed zero mA for that measurement. My next test measurement was at 3.3 mA. The AN8008 generally stayed at a reading of zero with an occasional jump up only to soon return to zero.
My next step is at 10 mA. By then I had a steady reading which was 8% low. At 30 mA the meter became useful with a reading which was only 1% low. By 75 mA and above the meter's surprising accuracy returned with the accuracy typically below 0.2%.
Fluke 87V | AN8008 | Error |
1.03mA | 0.0mA | - |
3.00mA | 0.0mA | - |
4.01mA | 2.0mA | -50.1% |
5.06mA | 3.6mA | -28.6% |
6.06mA | 4.8mA | -20% |
7.07mA | 6.1mA | -13.7% |
8.05mA | 7.3mA | -9.3% |
10.08mA | 9.5mA | -5.8% |
15.01mA | 14.6mA | -2.7% |
20.11mA | 19.7mA | -2% |
30.56mA | 30.2mA | -1.2% |