Electronic temperature switch 800 Smartstat series

programmableSPDTNPT 1/2

The Series 800 Smartstat is a microprocessor controlled temperature switch, transmitter and indicator, which enables several instruments to be replaced with a single device. * Pushbutton calibration of set points and transmitter range enables calibration on site without tools. * Programmable switching delays - the switching on or off (or both) of the relays may be delayed from 0.5 seconds to 15 minutes. This is particularly useful for preventing unwanted switching due to temperature transients. * Display of maximum and minimum temperatures recorded by the Smartstat. * Display of transmitter output in mA. The input temperature applied to the Smartstat is converted to a proportional electrical signal by the PT100 IEC751: Class A, platinumresistance sensor. After amplification this signal inputs directly into the analogue to digital (a/d) port on the microprocessor. The microprocessor continuously calculates the temperature from the input signal, compares this to the switch setpoints and operates the relays as required. If the temperature rises above the UPPER switch point the relay changes over from normally closed (NC) to normally open (NO), as the temperature falls below the LOWER switch point the relay changes over from NO to NC. In addition the microprocessor updates the LCD display of the temperature and the status of the relays. The typical response time of the relays to an alarm condition is about 125mSec.