The Dytran model 2180c, with steel construction, is a microphone in a charge mode. It has a high sensitivity of 600 pC/psi. The normal use of such a machine is to measure the high intensity of gas-borne sound pressure levels up to 191 dB. It works at high temperatures up to +500°F. A high temperature piezo ceramic material is used in its making. This generates a charge signal in response to sound pressure that acts on stainless steel diaphragm. There is a reduction of risk of spurious ambient vibration signals adding to signal output. The model also features internal ground insulation. This prevents AC noise pickup from external sources. This internal electrical isolation means that the sensing element is always electrically isolated from the mounting surface, and even from the diaphragm.