A101 Physical science cabinet clean-up

The cabinet was not in obvious visual disarray. Many boxes, however, were unlabeled mystery boxes. Boxes also often contained odd mixtures of equipment. Although the shelves were apparently once organized by topic, that organization slipped away slowly over the years. Springs were scattered across both cabinets on different shelves. Masses were in various locations. Office supplies were intermingled with chemicals.

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Of some amusement was this broken voltmeter, a piece of equipment that dates back to the Community College of Micronesia. I have a sense that the meter may have already been broken when it was carefully moved to the new campus in 1996.

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Historic and no longer working

After the experience of the loss of the electronic stopwatches, I moved the remaining voltmeters and ammeters into the air conditioned prep room.

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The portable sink and the location of the acid and micrometers

Under the portable sink and mirrored demonstration table I found an interesting tragedy. I had been looking for a micrometer or calipers to accurately measure small spheres. I was excited to find brand-new unused micrometers in shrink wrap plastic. Unfortunately they were stored next to a full bottle of muriatic acid - hydrocloric acid - that had clearly been there a long time. The fumes had seeped through the plastic and have corroded the core components. I have yet to determine whether anything is salvageable in these fine precision instruments. Even the apparently undamaged calipers has a rusted steel lock release pin. No item escaped the powerful acid fumes. I have moved the muriatic acid to the prep room, just under the shelves with the acetic acid. I also moved four propane cylinders into the prep room.

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All found together

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The damaged equipment

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Muriatic acid fumes can migrate through either plastic or cardboard

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One calipers destroyed, one with a rusted lock-release pin

To the extent that I can do so, I will work on acquiring a replacement micrometer and calipers. These will be stored in the air conditioned prep room to prevent the heat and humidity of salt air from destroying them. Fortunately my laboratories do not often require this level fo precision. Their primary value for me is to introduce students to the concept that for any given measuring instrument there is an uncertainty in the measurements made due to the resolution of the measuring instrument. Improved resolution does not remove uncertainty, only reduces uncertainty.

The left cabinet now contains mechanics. All boxes are labeled. The exception to mechanics is that magnets are on the bottom shelf on the right. Compasses, necessarily separate, are up on the second shelf.

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The right cabinet starts at the top with data gathering devices - measuring tools. Balances, rulers, protractors, mechanical stopwatches, and thermometers. The second shelf is primarily supplies of a general nature. String, cotton balls, sandpaper, thread, and pushpins. The sandpaper had been tucked in with the friction lab gear, but I use it more broadly. Although I had looked through the cabinet before, I had not realized that there was sandpaper in there. Two measuring devices are on the second shelf - bathroom weight scales calibrated in kg.

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Heat apparatus is on the third shelf down. The hot plate seen on the fourth shelf down was on top of micrometers next to the muriatic acid. It appears on an initial test to work, but I suspect the insides are probably in pretty poor shape after an unknown number of years of exposure to muriatic acid fumes.

The second shelf from the bottom is electrical laboratory equipment. The bottom shelf is chemistry and allied gear. The bottles of old liquids in the basket is of some concern. I discarded to the dumpster what appeared to be the oldest of the liquids. The four different bags of nails in four different locations was a puzzle. I can only guess that someone was using the zinc coated nails and the muriatic acid to produce free hydrogen.

I made an abbreviated attempt at working on the physical science gear in the prep room. The hour was late when I reached the geiger counter. The cover was off and bolted inside the case was a tape measure. I remember Cal Burgoyne using it in 1992, maybe it still worked. I realized I had a lot of work to do testing gear and trying to determine what might or might not work.