These temperature and resistance values are used to solve for coefficients a, b, and c in the SH-H equation (Equation 13), using a least-squares fit algorithm. Figure 10 shows the residuals (the observable estimates of the unobservable statistical error) when applying the resulting SH-H equation to a thermistor. proportional-integral controlled chiller/heater system controlled the temperature, using thermistor A1 as the feedback in the control loop. When compared to the set-point temperature, errors in temperature A1 should be the smallest and this was indeed the case, as we see in Figure 9.
As warmer weather taxes aging air-conditioning systems, the decision whether to repair an older rooftop unit or replace it with a newer, higher efficiency system may loom large for some commercial property owners. Most light-commercial HVAC products are designed for a life expectancy of 15 to 20 years.
Diesel Extended Life engine coolant offers the following advantages: 1  OEM approved. 2  Fully formulated; DOES NOT require initial charge of SCA. 3  Provides excellent liner cavitation protection.  Protects coolant system metals such as brass, copper, solder, steel, cast iron and 1  aluminum. Low silicate, phosphate and amine free.  Extended service life.