Digital Temperature Controller

PRIMA 721 is a Digital Temperature Indicator and Controller. Its single input accepts J-type (Iron/Constantan) and K-type (Chromel/Alumel) thermocouples, Pt100 RTD and linear (millivolt or milliamp) input. A large LED display on the front of the unit indicates either the process value or the user-defined setpoint, which is easily adjusted via a multiturn trimpot or membrane keyswitch. PRIMA 721’s single relay triggers heating, cooling, or high and low alarms for its single setpoint. This is a highly accurate controller, with an error as low as 0.1% for linear inputs and no more than 1% for thermocouples. PRIMA 721 is conventionally an ON-OFF controller that outputs a discrete signal, but can also be used in Time-Proportioning Mode which turns the actuator on and off for periods proportional to the desired control effort, to emulate a continuous actuator that can generate a control effort between 0 and 100%. It also retransmits a 4-20 mA output signal to other devices such as a Programmable Logic Controller (PLC) or Solid-State Relay (SSR). By including input terminals in the excitation loop, PRIMA 721 provides a power supply for two-wire 4-20 transmitters. The controller’s modular design has zero-wiring making it virtually shockproof.