Invitation to Tender for Displacement Vibrometer

The scope of this procurement is for a complete laser interferometer system (commercially referred to as a Vibrometer). This will include a laser interferometer instrument (laser head and driving boards), necessary third-party electrical equipment required to acquire signal data (oscilloscope, DAQ boards, PC-interface boards), software to operate the instrument on an NPL PC (or otherwise the tenderer to supply a computer where necessary) and physical hardware in order to integrate the instrument into the existing facilities at NPL (stand, tripod, objective lenses). Background to the requirement: The NPL requirement is for a laser interferometer for the displacement measurement of a water-borne reflective membrane incident upon by ultrasonic tone bursts. The purpose is to provide accurate and reliable picometre displacement measurements of the membrane, when driven at frequencies between 0.1 and 100 MHz, for the purposes of calibrating ultrasonic hydrophones. The measurement of displacement is expected to be robust to environmental laboratory noise including acoustic amplifier noise, typical RF bursts from pulsed lasers, air movement through air conditioning, airborne sound and environmental vibration. Access should be available to the raw data to allow for independent post-processing. The system should not be so bulky or sensitive that it cannot easily be moved once installed. The system will be expected to be used in multiple laboratories and as such must be suitable for efficient transport and set up.