Both connector types have the same exact measurements, the only differece is where the center pin is found.

For both SMA and RPSMA connectors, the female connector has the threads on the outside while the male connectors have the threads on the inside.

SMA male connectors has a pin in the center, the female connector has a hole.

On RPSMA, or Reverse Polarity SMA's, this is reversed, i.e. the pin is found on the female connector while the male connector has a hole in the center.

While RPSMA is typically used for Wi-Fi applications, there is no restirction on using it for other technologies.

In short:

Check if it is a male or female connector.

If the threads are on the outside it is a Female SMA/RPSMA.

If the threads are on the inside it is a Male SMA/RPSMA

To detemine if it is a standard SMA or an RPSMA connector, locate the center pin.

SMA - the male has the center pin.

RPSMA - the female has the center pin.