12-07-2017, 10:51 PM
The AN8008 (aka Zotek ZT109). About £15 delivered (including accessories).
Finally, the newest kid on the block. This meter is the same size as the AN8002, but has a number of improvements:
Having just checked, the frequency counter still gets to 80MHz.
The square wave output is 3V peak to peak - I haven't yet checked to see if it varies with battery voltage. It's from a source impedance of around 2k, and it's AC coupled, so symmetrical about ground. It's pretty clean. By pressing "SEL", you can choose from a range of frequencies from 50Hz to 5kHz. As I say, I'm not sure I'll ever use it, but perhaps it'll be of interest to the "makers" with their Arduino projects? The waveform is very clean and the frequencies are all spot-on.
Inside, it's very similar to the AN8008, but there are layout differences. Component quality is the same, but soldering is much better in this example. I note there is another switch (SW3), but no idea what it does yet. This one has an extra TO92 device, which is a precision voltage reference (ICL8069 - though note the incorrect silk screen!). Is that better than the internal one in the COB, I wonder? Otherwise, it's the same small ceramic fuses and MELF resistors.
I've only had this meter for a couple of days, but already I love it. I didn't think it would be possible to improve on the AN8002 without spending a lot more, but for an £3, you get improved performance, and the extra accessories. Perhaps in time, cheaper versions minus the accessories will become available?
Conclusion
These reviews have been dashed off in a hurry, so I'm the first to admit that I've not tested them as thoroughly as the Bsides and RS meter. However, I have actively used the AN8002 for several months now, so I'm sure that more rigorous testing won't bring any surprises. Also, it turns out these meters have been quite comprehensively investigated by others - just search - and no serious problems have surfaced in that time. So I'm confident about recommending these to those on a budget. Again - and sorry to repeat myself - these are for low energy bench use only. They claim 600V CAT III and 1000V CAT II (the AN860B+ actually claims CAT IV 600V). These haven't been independently verified (obviously, as this price point). In terms of construction, all these meters are much of a muchness, but they are disposable. With care, they should last well enough.
Hope this is of interest,
Mark
Finally, the newest kid on the block. This meter is the same size as the AN8002, but has a number of improvements:
- First, the colour scheme is better. Trivial, I know, but I really like it!
- It's a 10,000 count meter (9999)
- It has uA. And it has 10nA resolution!
- It has improved voltage resolution (1uV in the 10mV range). That's bench-multimeter territory!
- The temperature function has been replaced by a square wave output mode. That's of dubious merit, frankly...
- There is manual ranging!
Having just checked, the frequency counter still gets to 80MHz.
The square wave output is 3V peak to peak - I haven't yet checked to see if it varies with battery voltage. It's from a source impedance of around 2k, and it's AC coupled, so symmetrical about ground. It's pretty clean. By pressing "SEL", you can choose from a range of frequencies from 50Hz to 5kHz. As I say, I'm not sure I'll ever use it, but perhaps it'll be of interest to the "makers" with their Arduino projects? The waveform is very clean and the frequencies are all spot-on.
Inside, it's very similar to the AN8008, but there are layout differences. Component quality is the same, but soldering is much better in this example. I note there is another switch (SW3), but no idea what it does yet. This one has an extra TO92 device, which is a precision voltage reference (ICL8069 - though note the incorrect silk screen!). Is that better than the internal one in the COB, I wonder? Otherwise, it's the same small ceramic fuses and MELF resistors.
I've only had this meter for a couple of days, but already I love it. I didn't think it would be possible to improve on the AN8002 without spending a lot more, but for an £3, you get improved performance, and the extra accessories. Perhaps in time, cheaper versions minus the accessories will become available?
Conclusion
These reviews have been dashed off in a hurry, so I'm the first to admit that I've not tested them as thoroughly as the Bsides and RS meter. However, I have actively used the AN8002 for several months now, so I'm sure that more rigorous testing won't bring any surprises. Also, it turns out these meters have been quite comprehensively investigated by others - just search - and no serious problems have surfaced in that time. So I'm confident about recommending these to those on a budget. Again - and sorry to repeat myself - these are for low energy bench use only. They claim 600V CAT III and 1000V CAT II (the AN860B+ actually claims CAT IV 600V). These haven't been independently verified (obviously, as this price point). In terms of construction, all these meters are much of a muchness, but they are disposable. With care, they should last well enough.
Hope this is of interest,
Mark
