In keeping with the "Limited Information Transfer" in this thread, I suggest a Programmable Logic Controller, or PLC as they are often called.
The three major manufacturers are: Allen-Bradley, Texas Instrument, Siemens. Input interfaces available include: On-Off Voltage (AC & DC, Analog Voltage (AC & DC), 4-20mA Current; along with a multitude of sensors from various manufacturers.
You mention Logging. Does this mean to a printer, graphic display, mass storage device (what kind? hard disc drive, Solid State Drive, other?)
So far you are asking on the order of "I want to make marks on paper." That could be a $4000 high speed line printer down to grab a piece of charcoal and draw a line.
For instance you could use a bellows, a pencil, and have the pencil poke a hole in the paper when the pressure gets too low. That meets your stated constraints.
So far, we have no idea what you think you need or how it is to be presented as useful information.
If you want targeted answers, further define the problem and your constraints.
Cheers,
Tom