If you have a solid state relay and are wondering if its still good you might ask if it could be tested with a multimeter.
The short answer is no. Solid-state devices require a minimum amount of voltage/current across the input before the output device will conduct. Most multi-meters are designed to simply provide a small amount of voltage in order to measure the ensuing current draw. Therefore, when measuring a solid-state device, the meter will typically report an open circuit (or very high impedance) because it cannot put out enough to turn on the relay.