If there is nothing else in series with the current measurement, you are simply measuring the output voltage of the PSU, which shows 1V.
I dont see anything wrong with the picture...
Edit: Add 100 ohm resistor in series and see if you see a 10mV or 100mV drop.
If there is nothing else in series with the current measurement, you are simply measuring the output voltage of the PSU, which shows 1V.
I dont see anything wrong with the picture...
Edit: Add 100 ohm resistor in series and see if you see a 10mV or 100mV drop.
Burden voltage:
uA Range: 1 mV/ 1 uA
mA Range: 1 mV/ 1 mA
10A: 30 mV/ 1 A
Looks like somebody made a mistake in datasheet. A world will not stop because of this, data sheets are full of unidentified errors.
Looks like somebody made a mistake in datasheet. A world will not stop because of this, data sheets are full of unidentified errors.
It means that the resistance of the internal shunt on this range is 10 Ohms, which means a burden voltage of 10mV/mA which is not what the user manual says:
I suppose if Amazon can take it back for a refund, no real harm done (only to them I guess). And on that note, anyone got any suggestions for a replacement meter in a similar price range ($100-$150 USD)?
Fast forward a couple of weeks and I'm measuring the current on an LED. When I put the meter in series with the LED on the mA range, I notice that it is incredibly dim now, barely turning on. I get my other meter and measure 500mV(!) of voltage drop across the meter with a 50mA current. Bugger, the data sheet lied and it is actually 10mV/mA (or this unit is oddly faulty to that value).
Fast forward a couple of weeks and I'm measuring the current on an LED. When I put the meter in series with the LED on the mA range, I notice that it is incredibly dim now, barely turning on. I get my other meter and measure 500mV(!) of voltage drop across the meter with a 50mA current. Bugger, the data sheet lied and it is actually 10mV/mA (or this unit is oddly faulty to that value).
When you say "the mA range", what range? The meter apparently has ranges for 10 mA, 100 mA and 400 mA. They may have different input resistances.
Also, the lowest DC volts range appears to be 1000 mV, which sets the DC sensitivity. So if (for example) you want to measure 100 mA it is required to drop 1000 mV. So the input resistance would most likely be 1000 mV / 100 mA = 10 ohms on that range. That seems pretty reasonable to me. If the meter had a lower input resistance the accuracy would suffer. You have to choose what you prefer, accuracy or sensitivity?
It may be if you used the meter on the 400 mA range you would get a lower input resistance, and if you used the 10 A range you certainly would.
It was constant across all mA ranges, using the manual range function. I also did measure the resistance, and got something like 11.7 ohms on all mA ranges.
Most other meters get by with a ~1 ohm current shunt on the mA range, so there's no reason why this one should not. But my main issue is that they clearly state that it is 1mV/mA (1 ohm), which it absolutely is not.
If there is nothing else in series with the current measurement, you are simply measuring the output voltage of the PSU, which shows 1V.
I dont see anything wrong with the picture...
Amazon approved a full refund (plus some as they over compensated for shipping). So I'll probably pick up that Brymen BM257s fairly shortly.
TME wants a minimum of 20 Euro to ship to New Zealand, and shipments from Hong Kong actually tend to arrive fairly quickly to NZ, based on other eBay experience, so I'll go with Franky.
Amazon approved a full refund (plus some as they over compensated for shipping). So I'll probably pick up that Brymen BM257s fairly shortly.
TME wants a minimum of 20 Euro to ship to New Zealand, and shipments from Hong Kong actually tend to arrive fairly quickly to NZ, based on other eBay experience, so I'll go with Franky.
Are you using the US Amazon? If so, you could grab a Greenlee DM-510A if they'd ship it to you. It's a locally-branded version of the BM257 and goes for USD125.96.