In the world of high-end multimeters, the UNI-T UT8805E stands tall with its impressive build quality and top-notch components. In a recent teardown video, we got an up-close look at what makes this professional-grade instrument tick. The teardown process revealed a meticulously designed interior, with high-quality parts sourced from reputable manufacturers like Analog Devices, Texas Instruments, and Maxim.
The mainboard boasts a large, matte green PCB panel with ample space, showcasing UNI-T’s commitment to quality. One of the standout features is the AD7122-2 24-bit, sigma-delta ADC from Analog Devices, capable of sampling up to 31kS/s, although UNI-T has wisely limited it to 5kS/s for improved noise performance.
Complementing the ADC is the MAX6225AESA+ 2.5V voltage reference with an impressive tempco of 1.5ppm per degree C and long-term stability of 20ppm/1000 hours at 25°C. The analog section is a true marvel, with a plethora of high-quality components like AD8622 rail-to-rail op-amps, OP72 op-amps, an AD637 RMS converter chip, ADG1209 multiplexers, and a MAX333A quad analog switch.
Input protection is top-notch, with surge arrestors, metal oxide varistors, and beefy film capacitors. At the heart of the instrument lies a TRION T20F256 FPGA, responsible for sampling data from the ADC and managing the auto-ranging features and measurements. The front panel boasts an STM32F407 Arm Cortex-M4 application processor, handling data from the FPGA/ADC and managing the display and keypad.
While UNI-T acknowledged a couple of issues in the initial review, they’ve assured that a newer revision has addressed these concerns. A fresh unit is on its way for further testing, so stay tuned for updates on this impressive multimeter’s performance.