P-T Calculator is a comprehensive pressure/temperature calculation tool developed by National Refrigerants Inc. This iPhone app is designed to make the job of HVAC/R technicians easier by providing a range of unique features. Whether you need to calculate a simple pressure/temperature relationship or determine superheat/subcool temperatures, P-T Calculator has you covered.

One of the standout features of this app is its ability to automatically calculate and display values based on user input. Whether you input pressure or temperature(s), the app will instantly calculate and display the corresponding values. For refrigerant blends, P-T Calculator provides both saturated vapor and saturated liquid values.

The superheat/subcool screen includes a graphic display for blends, showing the entering, mid-point, and outlet temperatures, as well as the line temperature. This visual representation makes it easy to understand and interpret the data.

P-T Calculator also offers additional features such as automatic altitude correction (if location services are enabled), English/Metric units, and the ability to choose from a "favorites" refrigerants list. The app also provides supplementary information about refrigerants and links to the National Refrigerants Inc. website. Additionally, users can access the NRI Lubricant Cross Reference app and the NRI Branch Locator tool directly from P-T Calculator.

Overall, P-T Calculator is a valuable tool for HVAC/R technicians, providing accurate and efficient pressure/temperature calculations and a range of useful features. Whether you're a seasoned professional or just starting out in the field, this app is a must-have in your toolkit.