Second only to our knowledge of temperature control, Oven Industries prides itself on customer service. We work closely with our customers, from start up OEM’s to fortune 500 companies, to ensure the success of their products. From initial product design to after sales technical support, our customers are at ease knowing we are always willing to go the extra mile.
While Oven Industries has products that cover a wide variety of control types, we specialize in ON/OFF, Proportional and PID control. Put our custom designed algorithms to work for you, encapsulating the complexity of thermal management.
A simple yet functional control type; ON/OFF simply turns output on when the system falls outside of the designated temperature band. A good example of this kind of control is a thermostat. As long as the system remains inside the band, no power is applied to the system. Once the temperature falls above or below the band full power is applied until the unit reaches the set temperature; the cycle then repeats.
Proportional control offers a greater level of stability, as well as a reduction in overall energy used. Once the temperature band has been set, the unit calculates the percentage of power needed to meet the given set temperature. Any reading outside of this band will force the unit to be full on, but once the band is reached, a smaller percentage of power is used to get the system to slowly climb back to the proper temperature.
Proportional, Integral, Derivative (PID):
The most complex and accurate type of control, PID is an abbreviation for Proportional, Integral, Derivative. As an enhanced version of the standard proportional control type, PID calculates the system’s hysteresis to manage the temperature and ensure maximum stability. Proportional control can be slow to climb back to the proper set temperature, thus the integral calculation allows the controller to increase the rate of change to bring the system back to the set temperature faster. The derivative function monitors the change over a much longer period of time than the integral, which allows the system to more accurately compensate for rapid changes in temperature.
Oven Industries offers a multitude of sensor types to work in conjunction with our controllers for super fast and precise reading. The three main types of sensors are RTD, Thermocouple, and Thermistor. Most Oven Industries sensors are interchangeable within the specific temperature range for which they are designed – meaning in the event one is damaged, it can be swapped out with no need to recalibrate the thermal system. Custom designed sensors and probes are also available.
Resistance Temperature Detectors, or RTD’s for short, use resistance temperature characteristics to change value depending on the ambient temperature. RTD’s are widely used because of their accuracy and stability. Wire RTD’s are usually made of platinum wound in a coil and connected to a pair of leads. Platinum is used because it accurately supports the widest range of temperatures while keeping a very tight tolerance. This allows RTD’s to be monitored from longer distances than other types of probes with a higher accuracy. The nature of the wire RTD makes it a positive temperature coefficient, which means that as heat is applied the resistance value will increase. Many controllers Oven Industries offers can be used in conjunction with any typical RTD, and custom designed solutions can be built using any RTD specification.
Similar to the RTD is the thermistor. A thermistor is a temperature sensing device made of a semiconductor material that exhibits a large change in resistance for a small change in temperature. Thermistors usually have negative temperature coefficients, although they are also available with positive temperature coefficients. The main benefit of a thermistor over an RTD is that it has a larger range of motion, allowing it to cover a wider range of temperature. Oven Industries produces a wide array of thermistors as well as custom built probes to meet just about any requirement.
A thermocouple is a temperature sensing device made by joining two dissimilar metals. This junction produces an electrical voltage in proportion to the difference in temperature between the hot junction (sensing junction) and the lead wire connection to the instrument (cold junction). As the sensing junction and the cold junction are exposed to different temperatures, a millivolt potential is formed. This potential can then be calculated as a temperature based on the type of thermocouple used, the materials of the junctions, and the magnitude of the potential.