Abstract: A measurement apparatus includes a base having a top portion forming a fulcrum, and a rod-shaped body having a supported portion supported by the top portion, a pH sensor provided on one side thereof, and a reservoir provided on the other side thereof opposite to the one side with the supported portion therebetween, the reservoir being configured to store a fluid. When the reservoir is filled with the fluid, the rod-shaped body is balanced horizontally. When the reservoir is not filled with the fluid, the rod-shaped body is tilted to the side where the pH sensor is provided, so that the pH sensor is immersed in the solution in a water tank.

Abstract: An air conditioning apparatus includes an air vacuum pump that sucks in air from a prescribed space to place the space under negative pressure, a first hot and cool air tank that contains the sucked air, first valves that adjust the flow rate of air supplied to or discharged from the first hot and cool air tank, a second hot and cool air tank that contains the sucked air while an air flow from the air vacuum pump to the first hot and cool air tank is restricted, second valves that adjust the flow rate of air supplied to or discharged from the second hot and cool air tank, and a heating and cooling device that manages the temperature of at least one of the first and second hot and cool air tanks to which an air flow from the air vacuum pump is restricted.