chamber 166 through opening 167 and depending on their carbon dioxide concentration vary the output from thermistor 168 this variation is related to carbon dioxide concentration the signals generated by thermistors 168 and 169 are transmitted on leads 170 171 172 and 173 and the signals from semiconductor temperature sensing device 174 are transmitted on leads 175 176 and 177 to sensor board 133 where the signal is processed by the circuits of the sensor board and in digital form passes to the microprocessor via cable connector 132 see fig3 35 and fig2 fig5 53 show an alternative preferred embodiment of the security container 260 with an alternative preferred embodiment of the monitor control system 300 removably placed inside security container 260 the security container is fastened within insulated container panel 10 by means of flange 261 as fig5 53 show the security container monitor control system can be retrofitted to existing containers by simply forming an opening in front panel 10 of container 1 attaching flange 261 to container panel 10 and mounting security container 260 with its monitor control system 300 inside in that opening fig5 shows in front elevation view security container 260 adapted to receive the alternative preferred embodiment of the monitor control system of this invention the monitor control system of security container 260 has a flange 261 for securing the security container over an opening in panel 10 of container 1 as shown in fig1 screws or rivets inserted through openings.