Cycling power meter

A cycling power meter comprising:

• at least one sensor configured to generate at least one output, being at least one electric signal,
• wherein the at least one output is indicative of pedaling movement;
• a controller, the controller being configured to:
• store the at least one output in a memory,
• derive a cycling power based on the at least one output, and
• perform a zero-power calibration based on the at least one output in a non-load condition through the steps of:
• computing at least one statistical index relative to a quantitative change of the at least one output over time,
• storing the statistical index in the memory,
• evaluating whether the at least one statistical index A) falls or B) does not fall within a respective predetermined set of values indicative of a non-load condition suitable for accurate calibration, and
• performing the zero-power calibration only in case A) or not performing the zero-power calibration in case B) thereby improving accuracy of the zero-power calibration,
• wherein the controller is configured to compute the at least one statistical index through the steps of:
• a) obtaining samples from the at least one output by obtaining a numerical datum from the at least one output, when the sensor is a digital sensor, and/or by quantization of the at least one output, when the at least one sensor is an analogue sensor,
• b) computing at least one preliminary statistical index relative to a first predetermined number, M, of last samples among the samples,
• c) storing the at least one preliminary statistical index,
• d) repeating steps b) and c) until obtaining a second number, N, of preliminary statistical indexes, and
• e) computing the at least one statistical index relative to the preliminary statistical indexes.