Regular and accurate time frequency measurements are necessary to ensure that your laboratory and manufacturing processes are compliant to standard operating procedures. When location comes into play with you testing, accurate measurements of location and elevation are imperative, too. Advanced Test Equipment Rentals stocks Time & Frequency and GPS Calibrators to help you maintain standardized time, frequency, and location measurements, so that all instruments perform as required. Trust instrument measurements and results with every test. Rent Time & Frequency and GPS Receivers from ATEC.