How to generate an impulse to test a system's impulse response
One way you could do it is with a step input, and then differentiate the output. That will give you the impulse response. This is because a step input is much easier to prepare (a fast switching transistor, for example) than an impulse, and since the step response in Laplace means multiplying by 1/s, then differentiation means multiplying by s, thus leaving the transfer function, or the impulse response.
The differentiator can be as simple as an opamp with resistive feedback and capacitive input. If the time constant is not 1 then the output will appear scaled.