DT830D Digital Multimeter

The DT830D is a digital multimeter made in China. It is capable of measuring voltage, current, resistance, transistor, diode, and has a signal generator function, however, you should be aware that it cannot measure capacitor values. There are many branded versions of this meter all with the same model number, and I managed to find UNI-T, DOSS, Fuke, Haoyue, Nora, and Sunwa versions that were all similar to the one shown in this article and based on the same 830 series chip. This meter appears to have the ICL7106 Chip on Board (COB) package and the accuracy figures are very much similar to those of the DT830B.

The meter I bought was not supplied with a service manual, or instructions of any kind, and instead, the accuracy figures are printed on the back of the box. If you need more information regarding its accuracy, then please refer to the DT830B article. If you need a service manual, then I have a section on the ICL7106, which should be very useful because it has a multimeter circuit.

Please note that the model specification, and price, may change over time. The contents offering (such as box, manual, probes) may also differ between sellers; therefore it is advisable to search for the best offer currently available on auction sites.

Review

I decided to get this meter for three reasons; it has a very bright attractive colour, it has a signal generator function, and it was going for an introductory price of £2.50 including postage! I tested the voltage measurements up to 20 V and found them to be accurate. The resistance measurements up to 2 MΩ were also good enough for hobby use, and the signal generator function also worked fine. For the semiconductor tests, the transistor test function was adequate, and the diode test accurately measured the forward voltage drop!

The LCD is sharp and clear with thick and legible segments, including a HV symbol, and a negative symbol. This meter had the CE mark; however, if I remember correctly, it is a self-certification logo and does not constitute any type of independent formal testing.

Bad Points: You should be aware of some minor cosmetic issues. The probe plugs did not fit properly or sit straight. The front sticker for the switch was poorly stuck with an uneven finish.

LCD Contrast - Excellent

As you can see, the LCD contrast is wonderful! If you have a digital multimeter that was over five years old, then the good news is that they have made huge advances in LCD technology. There are very few LCD manufacturers, and therefore some of the high-end meters will also have the same display.

Fuse: Un-Fused Shunts

For the current measurement, the instructions on the back cover indicate that there is a fuse protection. However, when I looked inside, there was no fuse! A fuse is a very important safety component that should be included in all meters, and even some of the cheapest budget-end designs have them. Un-fused shunts mean that your meter has no way to protect itself from over-current situations. In such an eventuality, the PCB traces will burn, or the main chip damaged, and therefore your meter will not last very long. Since there is no fuse protection, the maximum current ratings may not be accurate either. On the meter, there is a marking indicating "200 mA max". Since there is no fuse protection, it made me wonder whether this was the rating of the PCB trace. This meter could get damaged if the setting is on 200 mA, and you pass 1-ampere through it by mistake. You will therefore have to be very careful when you are measuring current, or best not to use it at all for current measurement.

Probe Wire Resistance

The probe wires show a resistance of around 0.5 Ω and the quality appears to be the same as the earlier designs in the DT830 series. If you decide to use this meter, then you will need better quality probes, otherwise do not use the 10 A option to measure current because the wires will get hot. Even though my unit came sealed and brand new, the probes were making intermittent connections, so I contacted the seller and he was happy to provide replacement probes.

1000 V Arc Test

Although this meter has 200 V, 750 V, and 1000 V settings, I would not use this meter for any kind of high voltages in this range. For me to use it for higher voltages, I would require serious assurances, including arc test reports, and some heavyweight British safety certification logos before I would even consider it because the European CE mark on its own is meaningless to me.

The Sniff Test

I recently had an email from my good friend Avid -- a German Wikipedian -- who said that when he sniffed the plastic, he was seeing women... He was convinced that the Chinese were mixing chemicals into the plastic to make him see them... He even showed me photographs of his extensive meter collection that he used for sniffing purposes... I sniffed my unit, however I am sorry to report, Avid, that I did not see any ladies... :-)

Conclusion

Based on the excellent DT830B chip, this meter appears to have the same accuracy figures, and provides adequate readings. The plug and socket system on the DT830B seemed slightly better than on this unit, however, this information comes from a sample of ONE, which I recently bought. If they have made better batches, then you might get something completely different, and hopefully better. The factory is always making improvements to their production line, and chances are that they may have improved the design. In this case, it would be worth buying!

For non-critical and hobby use up to 20 V and 200 mA, this might be fine - but as Scotty always says -- "I cannot guarantee it though!" On the plus side, it has a nice cheerful bright colour, and for £2.50 including postage, it is a bargain! I would not be too surprised if this meter ended up selling in pound stores, in which case I would probably take five. This article continues, and in the following sections, you can see the inside circuit, case, selector switch, and more.

This Article Continues...