Which of the following is not a method to calibrate the ESCD?

The method referred to in the question that is not used to calibrate the Electrical Signal Comparison Device (ESCD) is the standard count. The standard count is not a calibration method for the ESCD, as calibration typically involves methods that allow for the adjustment and verification of equipment performance relative to established standards or known quantities.

Calibration methods such as the relative method, screed calibration, and core calibration are all specifically designed to ensure that the ESCD provides accurate and reliable measurements. The relative method compares the readings of the ESCD to a known reference, ensuring that the device's readings are consistent and reliable. Screed calibration is related to the calibration of the equipment used during the application of hot mix asphalt, ensuring that the mat thickness and tension are controlled properly. Core calibration involves taking asphalt samples from actual projects to calibrate the ESCD based on field conditions and materials.

By utilizing methods that establish a direct relationship between the device's outputs and known benchmarks, inspectors can maintain the integrity and quality of the asphalt paving process.