Kitchen thermometers for meat is the best way to tell if items are at the proper temperature. Time is acceptable for approximations but due to different calibrations of ovens the kitchen thermometer should have the final say in whether your pork roast has cooked enough. The usual parts of a kitchen thermometer are the probe that gets inserted into the meat and a read out of the temperature of some type.
These thermometers are made with a probe that contains a coil of two different metals that have different temperatures at which they expand. The coil operates a dial type read out and is the average of the two metals. These thermometers are oven safe and made to remain in the food during cooking time. The are of the probe that can accurately measure temperature is around 2 inches from the tip. a bimetallic-coil thermometer is good for thick meats such as roasts.
Thermocouple Kitchen Thermometers
Thermocouple thermometers have two thin wires at the tip of a probe that the temperature is measure and read on a digital read out. They can display a temperature in from 2 to 5 seconds. Because the reading of the temperature is in the tip of the probe thermocouple thermometers can be used with foods off all thickness especially thin foods. A thermocoupler does remain in the food while cooking.
A more recent technology called platinum resistive thermal device is quickly becoming a replacement for thermocouple technology. The Fluke FoodPro Plus is a new offering well worth looking into.
Thermistors Kitchen Thermometers
Thermistor type food thermometers are compact and product a reading very quickly. There is a ceramic semiconductor that measures the temperature, in the probe. The semiconductor is in the tip of the probe. The placement of the measuring device in the tip of the probe allows measurement of all thickness of foods. The temperature will appear in 10 seconds. Thermistor thermometers do not remain in food. The readout on the thermistor thermometer can be digital or dial.
Any of these types of meat thermometers can do the job. You need to know where the temperature measuring device is located in the probe.
The center of thicker cuts of meats will be cooler than the surface therefor take your reading from the coolest point of the meat.
If it is a boneless place in the center while a bone in item the temperature would be close, but not touching the bone. For instance a Turkey would be the thigh near the bone.
Always puncture the meat on top. Poking the probe in the side will leak those lovely juices that give flavor and moisture.
There are different models even among these types of meat thermometers. You do not have to spend a lot to buy a thermometer that does a good job.