Temperature Switches

Temperature Switches

Temperature switches provide discrete monitoring and alarming at a measuring point, supporting safe oversight of process temperature limits. Configurations commonly allow one or two switch outputs, or a combination of one switch output with one standardized analog output, and are offered with flexible process connections and options that include a transmitter and display; fast-response sensor designs (e.g., t90 on the order of seconds) support timely protective action.

Unlike continuous measurement devices used purely for control, a switch is often configured around a defined setpoint, hysteresis, and output behavior suited to interlocks, permissives, or alarms. In many installations, the switch output is used as a hardwired layer of protection, while the analog signal supports trending and diagnostics.

Benefits include simplified architecture for limit protection and reduced dependency on controller logic for basic safeguarding. Local indication and parameter access shorten commissioning time, and combining switching with analog output can reduce the number of penetrations and devices required at crowded nozzles.

Applications include overtemperature protection on pumps, compressors, heaters, and heat tracing circuits; temperature limit monitoring on hygienic and industrial skids; and alarm points on utilities such as steam, hot oil, and chilled water. Switches are also used where a simple, robust trip is preferred over complex transmitter and logic configurations.

Selection typically considers setpoint range, switching accuracy and repeatability, output type (PNP/NPN, relay, or solid-state), required approvals, and mechanical compatibility with the process connection standard. Attention to response time, insertion depth, and thermal coupling is essential so the switch reacts to the true process temperature rather than to localized conduction errors.

Instrumentation and Controls., an exclusive authorized representative of sales and service for Endress+Hauser.