If a given transformer has insulating fluid with a specific gravity greater than 1, from where should you draw a sample?

When dealing with insulating fluid in a transformer that has a specific gravity greater than 1, it is important to consider how the fluid layers within the tank will behave. A specific gravity greater than 1 indicates that the fluid is denser than water, which means it will tend to settle at the bottom of the tank.

Sampling from the top of the tank is the most appropriate choice because this area generally contains the least amount of sediment and particles that may accumulate at the bottom. Drawing a sample from the top allows for a more accurate representation of the insulating fluid's quality and condition, helping to identify potential issues such as contamination or degradation of the fluid.

In contrast, sampling from the middle or bottom may yield misleading results, as those areas are more likely to contain contaminants or settle materials that can distort the overall assessment of the fluid quality. Any sampling from different levels would likely not accurately represent the condition of the fluid, particularly in a situation where density plays a critical role in fluid stratification. Therefore, sampling from the top is the best practice for obtaining a clear and reliable assessment.