Over the last week at work we have been preparing an unused part of the facility for use. We need a place for an industrial freeze dryer and a walk in cooler. But first we had to clear out a massive pile of junk that had accumulated, and do demolition on a lot of old equipment and piping to remodel the space.
Demolition? Break out the sawzall! We used a big sawzall, a small pile of saw blades, an angle grinder with a diamond cutoff wheel, a bit of muscle and a lot of sweat to get it done. The pile of trash accumulated rapidly along the fence, old lumber, a lot of PVC pipe, and a lot of rust… A big dumpster will appear later.
Rust. This close to the ocean everything is badly corroded, do not even try to release the old bolts, just pop a fresh battery into the angle grinder and let the sparks fly. The 20 amp sawzall does not use batteries, good for the thicker pipes and framed walls, it rips through PVC like butter.
A series of very low tides had the lab gals looking to do some collection. Where? Right out in front of the office. With a “meeting” scheduled on the company calendar we went for a walk along the shoreline.
Aside from a morning sharing knowledge about sea life we did indeed find several specimens of Asparagopsis taxiformis to collect.
The usual drill… A problem that can be solved by a bit of circuitry. In this case the gals in the lab were having trouble controlling the mix of gas to their cultures. They needed to feed much less CO2 to the mix, where the off-the-shelf flow gauges and needle valves became difficult to use much under one liter-per-minute.
Simple solution… Build a gas modulator, something that could turn on the gas some percent of the time, allowing easy control of small amounts of CO2 to the mix. A timer and a gas solenoid… Easy.
There is nothing particularly interesting about the circuitry. A seven segment display, a few switches, and a power transistor to control an external solenoid. All very basic. It is the controller that is new, at least for me. An Arduino provides the programmable part of this project.