Hello,
There are several possibilities when creating an impedance matching network. The simplest ones I can think of would be to use a PI or T attenuator (3 resistors) or a matching transformer but there are other options as well. The attenuator is easy to construct but there is a minimum amount of attenuation that is determined by how far apart the impedances you are matching are. In the case of 95 to 50 ohm conversion you would have to attenuate your signal by at least 7.336 dB. This attenuation is easy to correct for in the NI scope software but you will have a lower SNR in your measurement which may or may not be acceptable. The matching transformer will not result in a power loss (although you will still have to compensate your measured voltage for the change due to the transformer turn ratio) but the transformer can not pass low frequency signals so this method will only work if you can deal will loosing the low frequency content of your input. Also transformers are tough to build yourself so you would have to find a vendor selling one that matches the impedances you want. 95 ohm isn't very common but there are vendors who can build custom transformers.
Another good possibility is to use the scope in the 1Mohm configuration and use a BNC T connector to connect a 95 ohm terminator to the end of the line. This will provide a pretty good termination but it won't be perfect because most BNC T connectors are designed for either 50 or 75 ohms. This means you will have a slight impedance discontinuity but it should still perform well. Some of NI's digitizers use separate signal paths for 50 ohm and 1Mohm to achieve better 50 ohm performance but the 5114 uses the same signal path for both so you should still achieve approximately the same performance with this method. Finding a 95 ohm BNC terminator will probably be difficult, but you can just use a BNC connector and solder a 95 ohm resistor between the center pin and shield or find a way to solder the resistor to the T connector directly.
Hopefully this helps you, just keep in mind if you use any of the matching networks I described above the voltage reading of the digitizer will need to be adjusted to account for the conversion. The easiest way to do this is to calculate the attenuation and feed that number into the "probe attenuation" input of the NI scope software and let it automatically adjust your data when it is fetched from the board. If you use the 1Mohm option with the T connector and terminator you won't need to worry about this at all.
Here is a link to a PI and T attenuator calculator:
http://www.rfcafe.com/references/calculators/attenuator_calc.htm
Regards!
-matt
