UT70B Teardown a.k.a. UltraDMM Development

As part of my development process. I ordered another Uni-Trend Multimeter from eBay. This time I got the UT70B model. I’ve seen it mentioned a few times online but I could not find any technical information regarding it. Specifically the type of chip that it uses. Additionally, because this meter offers features that the UT61E doesn’t, it’ll be a nice addition to the lab.

The UT70B model is quite a bit heftier than it’s UT61E brother. One of the features missing in the UT61E is the backlight feature, though it’s not quite near as bright as I thought it would be.

The RS232 interface is also slightly different from the one that comes with the UT61E. Though both meters offer electrically decoupled serial port connectivity which is great.

But enough talk. Let’s take this sucker apart and see what makes it tick. First step is to remove the plastic (latex?) sleeve. Interestingly, the foot stand for the meter is actually built into the sleeve and not the meter itself and so is the pocket for the RS232 interface, meaning it’s actually impossible to use the RS232 interface without it.

Just 3 screws hold the rear cover on.

Interestingly enough, Uni-Trend brands their own batteries. Nice touch.

The PCB is attached to the case by just the binding post screws. Easy enough to remove. Unfortunately, looks like the chip is buried underneath the LCD module itself.

The LCD module is held onto the PCB via 6 screws. The IR serial transmitter LED is clearly visible. Since the meter only transmits data and does not receive any input only TX led is required, no RX IR detector is present.

Carefully removed the screws and with just a little bit of force the rubber silicon connectors come off the PCB and off comes the screen.

And there it is. Cyrustek E51962Q is what drives this meter.

A quick Google search turns up the datasheet for this meter

Couple of minutes and the meter is nicely reassembled. Back to full working condition.

Now to implement the ES51962Q interface in UltraDMM.

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