1. One or more individual units may be provided to achieve the 64 channel requirement. For example, four 16-channel units or eight 8-channel units are acceptable.
2. Individual units must be supplied as a chassis mountable in a standard 19 inch equipment rack, or include an appropriate add-on rack mounting kit.
3. Individual units must be powered as a minimum by standard 120V/60Hz household line power. If units are DC powered an appropriate AC adapter must be provided.
4. Individual units must have as a minimum one sensor BNC jack per channel and one BNC output jack per channel. These jacks may be either on the front or rear of the unit.
5. Individual units must have a visual indication for each channel indicating at a minimum the status (good/bad/open) of the attached accelerometer.
6. Individual units must provide as a minimum on each channel, standard IEPE accelerometer power consisting of 4-10 mA constant current at 6-30 VDC to the accelerometer input. Each channel must be able to accommodate standard IEPE accelerometer AC output on a bias voltage of 8-12 VDC. A peak AC output capability of +/- 5 V per channel is required as a minimum.
7. Individual units must provide output per channel at unity gain as a minimum. Amplification and/or filtration of the output signal is not required.
8. Individual units must be capable of operation within the frequency range of 5 to 10000 Hz per channel with no more than 5% deviation in this range.

Individual units must be shipped with a current, NIST-traceable calibration certificate.