TickSize work for you?

Try their reference code

/api/reference/internals/symbol/ticksize

protected override void OnTick()
{
    Print("The current symbol has TickSize: {0}", Symbol.TickSize);
}

During backtest ( EURUSD tick data ) log results are 

10/08/2017 23:59:58.000 | The current symbol has TickSize: 1E-05

double pipSize = Symbol.PipSize;
            Print("DEBUG: Symbol Pip Size {0} ", pipSize);

During backtest ( EURUSD tick data ) log results are

10/08/2017 23:59:58.000DEBUG: Symbol Pip Size 0.0001