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Unformatted text preview: Experimental Practices
Setup and the Running of Experiments Unit Objectives Explore experimental hardware designing and construction issues Examine the procedures associated with the experimental setup Detail the experimental information that must be recorded Identify good experimental practices to minimize experimental errors and biases
2 1 Experimental Hardware Create accurate drawings – Needed for documentation – Allows changes to be made correctly Build to appropriated tolerances – To produce the correct phenomenon – To reduce experimental errors Where appropriate use rapid prototyping
– Use plastic parts and 3D printing
3 Experimental Setup Provide adequate grounding and shielding for signal wires Calibrate the instrumentation as accurately as possible Perform several test runs (sample size) Have good mechanical and electrical tool kits available Have a DMM and oscilloscope available
4 2 Equipment Ground Loop Chassis Ground Ground Loop 1 Ground Ground Loop 2 Ground
5 Ground Loop Free Circuit Chassis Ground Ground Ground
6 3 Experimental Operation I Record experimental parameters – Transducer serial number and sensitivity – Data Acquisition setting Scope: Voltage/div, Time/div., coupling, trigger information DAQ: Resolution, sample rate, number of data points, single/differential, filter cutoff – Equipment settings (e.g. bath temp.) – Environmental data (press. and temp.) – Take photographs of the equipment
7 Experimental Operation II Check Equipment setup (e.g. alignments for force transmission) Create an appropriate nomenclature for identifying individual runs Record experimental data
– Date, time, and run number – Experimental results where possible Good record keeping prevents the need to redo poorly recoded tests
8 4 Experimental Practices Follow the design of experiment scheme developed
– Randomize the runs – Perform replications Perform double blind experiments when required Rerecord all experimental parameters after any significant hiatus in the experimental study (e.g. next day)
9 Summary Care should be taken when building the experimental hardware, and running the experiments Ensure that appropriate mechanical and electronic tools are available to setup and perform the experiments Record as much experimental information and data as possible
10 5 ...
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This note was uploaded on 11/08/2010 for the course MECH 438 taught by Professor Johnl during the Fall '10 term at Manhattan College.
- Fall '10