Is there a way to compare the rain gauges to each other to detect recording errors?  Such as double mass curves or similar?

A double mass analysis is one method to compare cumulative rainfall from various rain gauges where consistency between rain gauges is deemed an indicator of proper operation.  Keep in mind that a double-mass analysis is generally intended for use evaluating data over long time periods, not individual rainfall events.  For example, you could look at cumulative rainfall over a rolling 12-month period.  Based on past literature reviews, rain gauges are considered to pass the double-mass analysis if they are within ±20% of reference or within ±20% of each other.