An unusual bit of test gear, for an industry few will use.

[SeanB]

Decided to see what is inside this bit of arcane test equipment. Test gear, but while it is electronic, the use is definitely biological, and it has only one use.

Hennessey meat grader, what is used to set the quality of the meat you buy. Push the probe into the meat, and this machine does some arcane work with sensing in the probe, using an optical sensor in the front as it goes through, involving detecting fat content, colour and water content, then makes a decision as to what grade will be applied to the meat. Thus there is a need to attach a printer, probably a serial one via the power cord, and print out the grade, A, B, C and the class 1, 2, 3 of the meat, that is then used to run a coloured ink roller down the side in a line, to show, even after it has been sliced up into smaller parts, the grade of the original.

Cleaning is to remove stuff from the front, then wash to remove "debris" with hot water, and then an inner housing on the electronics to keep them dry, with the 68705 CPU, with 16k of memory, and the external program EPROMs as well, plus the interface to the rest of the unit. Bottom board with the analogue stuff, and probably using some form of ADC to communicate with the CPU, and the isolated serial interface to the printer. 555 timer there as well, probably doing reset.

Definitely something is wrong, either there is another board hidden in the front, which does power conditioning, as 3A is a little high for power draw, though it does have sensing, so it knows when the probe is pushed into the device under test, and the speed of this, so it likely does evaluations on all aspects, rating according to depth as it goes in. According to the manufacturer, up to 200mm per second for the current models.

Power up and it does sort of work, but without the other half, which I do not have, it remains a curiosity, made likely 1999, from the date codes, and never being repaired in this time, though there are a few minor revisions on the board, where there are extra components added, probably due to earlier ones having common failures.

Still being made, though a much newer model, with some improvements made on it.

[SeanB]

More pictures, last ones.