Our VP for Sensing Fluid Pressure called this sensor from Kavlico “sweet.” Needs a 5VDC 20mW power source, and will likely put out 0-4VDC, contingent on pressure, from 0-5"/H2O max, we’d say. Measures 1-5/16" x 17/32" on a pair of 7/8" long 5/32" slotted mounting wings. The upper 3/16" OD barb is the low side, and the lower is (ironically) high. Has a 3-pin connector with legend on the back for power and output. Call for a data sheet.

It's a nonpolarized bimetal heat sensor, 1/2" long with rubber sleeves and 6" long leads. It's also mysterious, because when used as a thermocouple multimeter input, it reads approx 94° in nearly boiling water but approx 170° in ambient air. Wethinks some sort of inversion or scaling is going on, but a person with your smarts will surely figure it out.

This 4" x 3-3/4" x 1-3/4" medical take-out air sensor has (3) ports coming off the main 3-1/8" x 3/4" ID chamber, (2) leading to one sensor and the other leading to a second one, then through circuitry on a mounted PC  board leading to a 10-pin output connector. Also has a PCB-mounted 3V coin cell battery. The sensors have input, output and trigger voltage and a voltage output, but we have no specs. Nice parts and pieces, though.

How many what? Well, whatevers, as long as you can count them, which you’ll be able to do with this 24VDC, 1.7W, 6-digit, pulse-activated, non-reset counter. In a 7/8” x 1” x 2-3/8” clear acrylic case with a mounting arm and a quick-disconnect terminal on 4” leads.