c. Preventive Maintenance.
(1) Before using cylinders, check to make certain that cylinders are undamaged, that connection threads
are clean and undamaged, and that all connections are tight. Do not attempt any repairs on defective cylinder or
cylinders with defective connection threads. Turn in defective cylinders to issuing agency for replacement.
(2) Do not use or attempt to repair defective pressure regulators; if defective, turn in to issuing agency
(3) Do not lubricate cylinder valve or pressure regulator.
(4) When cylinders are empty, take cylinders outdoors or to a well-ventilated area and open cylinder
valves. Never open valves while cylinders are in the laboratory. When certain that cylinders are empty, close valves
and replace outlet-connection caps and valve protection caps. Turn in cylinders to issuing agency.
Before proceeding, always keep in mind the WARNINGS listed in the front of this manual.
Never attempt to refill a cylinder, return it to the supplier.
2-30. ANEROID BAROMETER.
a. Description. The aneroid barometer, designed to comply with the requirements specified in ASTM Method D86,
is wall mounted in the laboratory. It is a temperature-compensated instrument and is graduated in both English and
metric systems, from 26 to 31 inches (72mm to 78mm) of mercury. Pressure graduation is 0.10 inch (0.254 mm) of
mercury. It can be used for altitudes sea level to 3500 feet (1066 meters).
b. Operation. Figures on dials 26 through 31 represent inches of mercury, the standard means of expressing
atmospheric pressure. Read the indicating hand closest to the dial which responds readily to any change in atmospheric
pressure. Use the set hand to note any change in pressure. Position the set hand directly over the indicating hand. A
few hours after setting, note any change in pressure. A rise in pressure is indicated by movement of the indicating hand
to the right. A fall in pressure is indicated by movement of the indicating hand to the left.