APZ 3230 is based on a silicon piezoresistive sensor without media isolation diaphragm and therefore is capable of measuring very low pressures and vacuum. Compatible with non-aggressive and non-corrosive gases and low viscosity oils, APZ3420 has a great long term stability and reduced temperature error comparing to the traditional models with diaphragms. Dry sensor makes this model preferable in applications where media contamination with filling oil is not desirable.