Selecting a pressure switch requires matching the technical specifications to your specific medium and environment. Key factors include the set point range, deadband (differential), and maximum system pressure. For hydraulic systems, prioritize piston-actuated switches for high-pressure durability; for pneumatic or low-pressure gas systems, diaphragm-actuated switches offer better sensitivity. Always ensure the wetted materials (e.g., Stainless Steel, Brass, or NBR) are chemically compatible with your fluid to prevent corrosion and premature failure.