26.10.2010 21:22


This is my small personal review ot this meter.

UT81B is declared as a kind of scopemeter - it is a multimeter with some basic oscilloscope functions. It can be either battery powered or it has also 6V/450mA DC adapter. It has opticaly sealed USB transfer, can measure DC V up to 1000V, AC up to 750V, resistance up to 40MOhm, frequency up to 10MHz (probably sinus), bandwidth for UT81B is "only" 8MHz (UT81A only 2MHz - thats probably the difference) with 40MS/s giving resolution 100ns/div - 5s/div with 8bit ADC, capacitance 100uF, AC/DC current 10A. Of course it has also a diode and continuity test. Inacurracy is overall around 1%. That's what documentation says.

Few words about meter and it's usage:

This is Linux identificaton:

usb 2-8: new full speed USB device using ohci_hcd and address 3
usb 2-8: New USB device found, idVendor=1a86, idProduct=e008
usb 2-8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 2-8: Product: USB to Serial
usb 2-8: Manufacturer: WCH.CN 
generic-usb 0003:1A86:E008.0002: hiddev96,hidraw1: USB HID v1.00 Device [WCH.CN  USB to Serial] on usb-0000:00:02.0-8/input0

It looks the USB is in general only USB to serial port converter.

I've got a description of communication protocol from UNI-T. It confirms this is only serial port. Here is the description of UT81B protocol.

Uni-Trend ut81b

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