Field pressure recorders should have weatherproof cases of fiberglass-reinforced plastic or aluminum. Colored epoxy or baked vinyl is used to provide a textured finish. If the case contains electrical components, it should meet the electrical classification requirements for the area. The pressure element should be suitable for the process pressure and fluid.
The range should be selected so that the normal process pressure is in the middle third of the chart. If suppressed-range pressure recorders are specified on critical applications, such as compressor suction or discharge, a full-range pressure recorder should also be provided. A dual-pen, dual-range recorder may be used instead of a full-range recorder.
The process connection should be ½-inch female NPT. The chart should be 12 inches in diameter. The case should include a socket or yoke for mounting on a 2-inch pipe. The typical chart drive has a 7-day rotation and a clockwork drive with an 8-day wind. Electric and pneumatic chart drives are also available.