Model 1201 smart sensors allow for the measurement of temperature and relative humidity, (RH) during an ILRT without the aid of a data acquisition system. Each compact sensor contains one
temperature channel and one temperature compensated RH channel with its own CPU, memory, signal conditioning, internal calibration constants and RS-485 bus interface.
The RS-485 network allows for multiple sensors to be connected to a PC's communications port with a single 4-wire cable string. A typical ILRT may use six strings with seven or more
sensors per string. Although the sensors are physically connected in series, they are electrically connected in parallel so that the failure of any one will not affect the others.
The advantages over a conventional system
• Elimination of the need for a scanner and data acquisition system.
• The amount of cable and the time needed to install it is greatly reduced.
• Each sensor is a complete system in itself; a single failure will not disable the entire network.
• Each sensor may be subjected to an end to end calibration in the laboratory.
• The sensor directly outputs a digital signal, cable length has no effect upon the sensor's accuracy.