Folks,
I have taken a look at the guts of the Owon B35T and posted a few photographs here;
https://flic.kr/s/aHskcEJ9Yf.
I also did a little bit of testing which is considerably less than exhaustive and certainly not tracable to any kinds of standards. It might be useful to someone but take it all with a pinch of salt...its really just a quick looksee and I reserve the right to backpeddle on anything I've written here! If anyone wants any specific tests carrying out, or a little more certainty, and I've got the kit to do it then drop me a note and I'll see what I can do.
Note that I've not tried the Bluetooth functionality yet. In the past some have suggested that it could interfere with readings, but that will take quite some investigation.
- Leads read 0.4 Ohms on resistance range. Quality is OK but certainly no Fluke.
- Resistance reading settling time is around 2 seconds
- Plastics are medium quality. Not great, but certainly not terrible. I don't think the stand on the back will put up with a huge amount of abuse, but it will be fine for home use. The blue 'soft touch' surround is fine. In comparison with UT61e I would say the quality feels slightly less, but there's not much in it.
- Switch knob is positive, but not quite as smooth as the UT61e.
- Screen size is really nice.
- I like the external fuse in the battery compartment. Internal ceramic fuse is rated at 20A/250V.
- Backlight is great while its on, but useless because it switches off after 10 seconds :-(
- When abusing the meter with a high frequency square wave it seemed to 'crash' and wouldn't update the display until I switched to another range and back again. I wasn't able to reproduce the problem despite a fair bit of trying.
On Ohms, tested against Picotest 3500A, Calib 31 Aug 2012;10 Ohm nominal resisistor reads 10.1 Ohms, Picotest reads 9.886 Ohms.
120 Ohm nominal resistor reads 118.7 Ohms, Picotest reads 118.700 Ohms.
10K Ohm nominal resistor reads 984 Ohms, Picotest reads 980.27 Ohms.
[Ranges are 600.0/6.000k/60.00k/600.0k/6.000M/10.00M/60.00M Ohms, Spec is+/- 0.8%+2Dig except on 60MOhm range where its 3Dig]On DC Volts, against calibration source (calibrated against Agilent 34401A) and Picotest as above;2.50002V source reads 2.494V, 2.5000V on Picotest.
5.00114V source reads 4.988V, 5.0011V on Picotest.
7.50002V source reads 7.51V, 7.4999V on Picotest.
10.0052V source reads 10.01V, 10.0004V on Picotest.
Ranges are 60.00mV/600.0mV/6.000V/60.00V/600.0V/1000V. Spec is +/- 0.8%+2Dig.Frequency, square wave, 50% cycle, uncalibrated Rigol DG1022;1Khz source, 0.999KHz indicated
2KHz source, 1.999KHz indicated
10KHz source, 99.98KHz indicated
500KHz source, 499.8KHz indicated
1MHz source, 999.7MHz indicated
5MHz source, 4.998Mhz indicated
Sine wave (the source I had to hand will only do 5MHz square wave);10MHz, 9.997MHz indicated
20MHz, 19.99MHz indicated (Note, manual only claims operation to 10MHz).
Ranges are 9.999/90.99/999.9/9.999k/99.99k/999.9k9.999M Hz, Spec is +/- 0.8%+2Dig.Duty cycle (1MHz square wave);50% source, 50.1-50.3% indicated
20% source, 33% indicated
30% source, 39% indicated
70% source, 62% indicated
Duty cycle (10KHz square wave);20% source, 20.2% indicated
70% source, 69.6% indicated
Duty cycle (1 KHz square wave);20% source, 19.9% indicated
80% source, 79.9% indicated
Spec is 0.1-99.9%, +/- 1.2%+3Dig for <1kHz, +/-2.5%+3Dig for >1kHz.Temperature; Reads my body temp as 36 DegC. Not dead yet then.
Range is -50DegC to 400DegC, 1Deg resolution +/- 2.5%+3Dig.Edits;4 Jun: Addition of spec/range information.