This 3½-digit 2000 count manual-ranging heavy-duty multimeter is an interesting example of mid-80s technology. With an impressive safety-yellow thick sturdy o-ring and gasket-sealed case, it looks like it could survive a drop test with the only damages being to the floor it lands on. Ironically, the most serious damage to be repaired was not electronic, but a broken internal screw post, perhaps due to age and over-tightening.
It arrives in malfunctioning condition, flashing random numbers on voltage ranges, and alternating between random numbers and ‘OL’ on any resistance range. A simple IPA cleaning of the LCD-main chip assembly restores functionality. In addition, a precision resistor was found to have a broken lead, and some questionable soldering was cleaned up.
Other interesting facts and observations about the Beckman HD110:
- The highest voltage ranges are 1500VDC and 1000VAC. It is not CAT-rated since it pre-dates the standard.
- Battery life is specified at an impressive 1500 hours. The meter only draws 282μA in DCV mode and 331μA in ACV mode.
- The continuity tester includes an omega (Ω) LCD annunciator.
- The continuity tester only emits a short beep upon initial connection and not a continuous tone. The threshold is very high at around 500Ω for the 200Ω range, indeed it will indicate continuity even while displaying ‘OL’.
- The smaller fuse is inaccessible without removing the circuit board.
- The 9V battery is supposed to be accessible by just removing the cover and the large fuse, but is essentially impossible to remove and re-install without also loosening the circuit board.
- The tilt stand is remarkably fragile compared to the rest of the case. It works well, however, and can be re-positioned as a hanger.
- Later versions of the model have been sold with Wavetek, Meterman, and possibly Amprobe branding.
DMMCheck calibration check results for this Beckman HD110:
|AC||5V||5.55||nominal for non-TRMS|
|1mA||1.112||nominal for non-TRMS|
|Ohms||100Ω||100.3||0.3 with leads shorted|