Both of the modules you mentioned have built in cjc sensors. You mentioned the 1303 terminal block then later called it a 1300. The 1303 should have a more accurate cjc reference than the 1300. I have not used the 1112 but since it is designed specifically for Thermocouple measurements they should have a decent cjc sensor network. I will mention that the miniconnector plugs should be the right type for the T type you are using but I imagine you have done this.
In the scan mode your 1102 module will continue to scan the cjc so changes in ambient temperature at the chassis should be compensated for. Since the 1112 are newer module they should do the same. Some of the older isolated modules only picked up the cjc reference at on the initialization of the scan. I have used the 1102 modules with the 1303 terminal blocks for several years. The accuracy of this combination usually keeps me within a couple deg F. when I check the system. If you are using the 1303 terminal block make sure you have the right resistor network for your application. Check your documentation for if you have the 10 ohm bias resistor in and your tc is grounded you will see a significant error. There are ways of using an external CJC to improve your accuracy if needed. These methods will increase the cost of your system, as they will require additional hardware.
