You need a ‘set up’ for probe-logging the temperatures. The reason is; you need to understand the progression of heat and temperature fluctuations in your oven or simply to measure core temperatures to finish at the precise time.

This will help you begin to understand what happens when you spend hours preparing a meal and then you over cook or under cook it. Try to see these tools which will cost you no more than a few hundred dollars.

Thermocouple Logger: Model TC101A
http://thermoworks.com/products/logger/index-logmaster-th.html

Miniature Needle Probe
Model: 113-181/113-182/113-183/113-184/113-185
http://thermoworks.com/products/probe/tc_penetration.html

Oven Cooking Probe: Model 113-170
http://thermoworks.com/products/probe/tc_penetration.html

Therma Differential Thermocouple Meter: Model 231-022
http://thermoworks.com/products/handheld