Potting moisture detection system and method

A node, comprising:

• a circuit board assembly comprising a circuit board and a processor mounted to the circuit board, the processor comprising a pin and an analog-to-digital converter (ADC) in electrical communication with the pin, the circuit board defining a test point formed therein, the test point electrically communicating with the pin via a trace covered with an insulator;
• and
• a non-transitory memory resource, the non-transitory memory resource having computer-executable instructions stored thereon that, when executed by the processor, cause the processor to
• apply electrical charge to the test point after the circuit board assembly has been encased in a potting compound, and
• command the ADC to read a test point voltage at the test point, the test point voltage indicating voltage of an equivalent resistor-capacitor (RC) circuit comprising the insulator as an equivalent capacitor and the potting compound as an equivalent resistor;
• wherein the processor further comprises a switch configured to selectively assume a first position, a second position, and a third position, the first position bringing the equivalent RC circuit into electrical communication with a voltage source, the second position resulting in an open circuit between the voltage source and the equivalent RC circuit, and the third position bringing the equivalent RC circuit into electrical communication with an electrical ground;
• and
• wherein the computer-executable instructions, when executed by the processor, further cause the processor to
• selectively bring the switch into one of the first position, the second position, and the third position,
• implement a switching sequence between the first, second, and third positions to result in a pulse train, the pulse train having a length of high pulses, the length of high pulses being proportional to a first magnitude of electrical charge to be applied to the test point,
• read an ADC value at an output of the ADC, the ADC value expressed as a number corresponding to the test point voltage read by the ADC,
• apply a subsequent magnitude of electrical charge to the test point, the subsequent magnitude of electrical charge corresponding to the ADC value,
• repeat, for a predetermined number of iterations, a sequence of reading an ADC value and applying a subsequent magnitude of electrical charge to the test point, and
• determine a point value average over at least a portion of the predetermined number of iterations,
• wherein the point value average provides an indication of conductance of a combination of the potting compound and the insulator, from which relative moisture content in the potting compound can be ascertained.