What affects insulation resistance reading?

Insulation resistance readings can be influenced by several factors, including temperature, humidity, and the presence of contaminants such as dust or moisture on the insulation surface. The age and condition of the insulation material also play a crucial role, as deteriorated or damaged insulation can lead to lower resistance values. Additionally, the testing voltage used can impact the readings, as different materials may respond differently to varying voltages. Lastly, the test environment and the type of insulation being measured can further affect the accuracy and reliability of the readings.