Sentinel System

Temperature Controller and Monitor

GMRT antenna shells are equipped  with highly intelligent sub-systems to provide the best results to the Observatory. About 95% of the sub-systems involve only electronics. Hence all the sub-systems are working inside the antenna shells with great care and attentions under highly temperature controlled environment.

GMRT Temperature Control & Monitor is monitoring the remote antenna shells temperature in the Control Room at Central Electronics Building through Optical Fiber Network. It has direct digital display read out for shell temperature right at the antenna base.

GMRT Temperature Interlock is activated in all the antenna shells to avoid over temperature inside the antenna shells due to Air Conditioning failure.

Features :

# Continuously  Monitors the temperature at the Antenna shell and transmits the data to the Control Room.

# National Semiconductor make LM-35 (0-100 degC) is used as the sensor in the system.

#Sensor output voltage varies at the rate of 10mV/degC with maximum resolution of 0.5degC.

# The system has facility to automatically shut down the shell power when the temperature goes beyond a threshold level.

# An online program has been developed to display the Antenna  temperatures in the Control Room.

# The program also gives an Audio warning in the Control Room and the Antenna name is flashed on the Computer screen.

# Generally the temperature goes up due to some failure in the Air conditioning system.

# High temperature due to Receiver system over heating has not been observed so far.