The version of this experiment that I did during college used a light tight box with a light bulb on one end that had the intensity controllable on the outside then about a third of a meter down was one slit that focused the beam into a strip of light then about 10 cm after that slit was the double slits right in front of the double slits was a blocker that had a hole in the middle of it that was wide enough to allow light from both slits to go through when the blocker in the middle. The blocker also could be moved by turning a knob on the outside to block one or both of the slits. This could be said to be the detector at the slits.
On the other end of the box we had a photomultiplier tube to detect the photons admitted by the light bulb and the tube could be moved across the end of the tube and based on the frequency of the photons we could determine intensity of the light at that point. This was the detector at the end of the box.
We saw the wavelike properties of light when both slits were allowed to go through but when one of the slits was covered we saw particlelike properties.
There were other slightly different setups for this experiment that we went through including using a laser for a light source and using a photodiode as the detector at the end. Each different method produced similar results.