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Most embarrassing junior tech moment? Go!

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Black Phoenix:

--- Quote from: TERRA Operative on May 12, 2023, 12:25:45 pm ---Oh, another one.

Back when I was in the water treatment game, we were servicing the UV sterilising system that would disinfect the water as a last step before leaving the sewerage treatment plant back into the ocean.
The UV tubes were long quartz fluorescent tubes without the phosphor (like a massive UV EPROM eraser tube) all racked up in quartz 'test tubes' with double o-ring plugs in the end and submerged into the canal.
IIRC there were 2 banks in sucession, each consisting of 4 racks wide each holding 12 tubes arranged 6 tall, 2 wide.

We were cleaning the insides of the tubes as the UV light along with the small amount of moisture leakage and other science reasons forms a brown coating on the quartz 'test tubes' which requires the use of phosphoric acid to clean off.

The guy I was working with wasn't wearing gloves, which I warned him about but because the acid didn't immediately burn, he dismissed my warnings and said he's fine.  :popcorn:

Well..... the next day... his hands looked like they had been underwater for a week and the top layer of skin was sloughing off.
Dude basically gave himself an epic chemical exfoliation.  :palm:

He wore gloves religiously after that. I bet his hands were sensitive for aaageess  :-DD

--- End quote ---

Had a similar situation when I was working on the CNC machines. The company also were selling UV treatment equipment, from Hanovia.

I didn't do instalation of the equipment but the preventive maintenance, replacement of seals, lamps, quartz tubes etc was done by the maintenance team. I had a little of phosphoric acid fall on my arm skin and heck did I look like a snake sheading skin...

srb1954:
Back in the olden days when I first started using CMOS devices I found that debugging such circuits was a little different from the TTL circuits I had previously been used to.

I had a new logic board for testing but was having some trouble to get it working correctly. It seemed to work most of the time but for some combinations of inputs the logic gave incorrect results. After wasting a few hours checking and rechecking the logic design I realised I had forgotten to turn the PSU on when starting testing that morning!  :palm:

The whole board was being powered by the pulse generator providing the clock input. There was enough current being coupled through the protection diodes on the clock input chip to power the logic most, but not all, of the time.

ShaunT:
Well this was at college but it was a job our tech should have done.
I was ahead in A level electronics so while everyone was on TTL and playing with transistors I had moved onto CMOS gates. We shared a power supply with a box termination in banna sockets. So my circuit kept false triggering and placing a local electrolytic cap did not work. So I fitted electrolyic caps to ALL boxes. Then someone for a joke swapped the leads to the power supply which normally only kills a couple of projects but this time the ALL the boxes exploded with plastic shower of shrapnel. I was in another lesson and watched as this very stunned kid was taken to headmaster for causing so much damage.
That's how I learned about decoupling and one electrolyic is not enough and may need to add sat a ceramic rather than keep having bigger capacitance!
Back in the eighties when we could not afford individual power supplies as cheap as now and just have one big one for all which I think came from a telephone exchange!

armandine2:
mildly embarrassing moment

company made bespoke SPC (statistical process control) test measurement rigs with LVDT transducers. I removed one of a rig's component blocks from a unit without first removing the two LVDTs which were in that block. In doing so I sheared the tip ends of the LVDTs  :palm:

I still blame the poor design. Though it was a good unit - used on Ford Galaxy ignition block die castings.

madires:
The small and harmless things can be quite entertaining too. At the university we had a few computer rooms including one with SPARstation IPCs (small Unix workstation, see https://en.wikipedia.org/wiki/SPARCstation_IPC) and large Sun CRT monitors. The IPC comes with a 3.5" floppy drive. For one course we had to write some unix shell scripts and save them on a floppy disk. So you insert the floppy disk, copy the scripts, and then you suddenly realize there's no button to get the disk out of the drive...

There's a shell command to eject the floppy disk.

The large Sun monitors came with remote controls, similar to the small ones for car stereos or LED controllers. Of cource they were locked up in some drawer, but a student working as tutor had one. And he had a lot of fun with his RC and some students he didn't like.


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