The Value of Parts, Materials and Processes (PMP)

To ensure consistent success, proper design and fabrication are controlled through Parts, Materials, and Processes (PMP). Strainsert documents and utilizes special PMP controls to ensure all unique requirements are met.

Parts

Each job includes a list of pre-approved design parts. Procurement of traceable parts is done only through authorized suppliers and distributors to help mitigate counterfeit parts from entering a subassembly or product installation. Further, controls are in place to ensure similar yet prohibited substitute parts are not unintentionally installed. Parts are tracked, as needed, using data such as supplier name and CAGE code, part numbers, lot-date-code, and batch number.

Examples of parts include circuit boards, relays, switches, connectors, strain gages, resistors, wires, and cables.

Materials

Each job includes a list of pre-approved design materials, in addition to using customer approved materials, when required. Materials are categorized as either Metallic or Non-Metallic. Both metallic and non-metallic materials will be traceable based on requirements. Traceable data can include supplier name and CAGE code, part numbers, lot-date-code, and batch number.

Shelf-life and contamination controls are in-place to ensure that exposed and/or expired materials are not used.

The metallic material for the Force Transducer body will include a specific, fully traceable, material certificate. Other examples of metallic materials include solder, nuts, bolts, screws, washers, standoffs, fasteners, inserts, seal plugs, and wire conductor.

Examples of non-metallic materials include O-ring/gasket seals, wire insulation, protective and insulative wire sleeving/tubing, tape, film, adhesives, cement, epoxy, solder, resin flux, coatings, paint, and potting compounds.

Processes

Each job includes a sequence of required processes including design, fabrication, test, marking, and packaging.

Design Process

Strainsert designs all its systems in-house using CAD software and in-house proprietary methods. For each custom job, a detailed drawing is generated for customer review and approval. This drawing includes dimensions and tolerances, loading direction, capacity, parts, materials, specifications, cabling, electrical output range, instruments, connections, and wiring.

Fabrication and Test processes

Prior to assembly, metal material may require specific treatments. These treatments include surface grinding for tighter tolerances, heat treating for specific hardness, and anti-corrosion treatments, such as hard coating, plating, passivation, and anodizing. Post treated metals may then be tested for defects.

Metal material testing may include both destructive and non-destructive (NDT) processes. Destructive testing may include Hardness testing (Rockwell, Brinell, Vickers), Impact (Charpy V-notch), or Ultimate Tensile Strength. NDT testing may include Liquid Penetrant, Magnetic Particle, Hydrostatic Pressure, Ultrasonic Testing, or X-Ray Inspection.

Assembly steps are done by our IPC J-STD-001 (including the Space and Military Applications Electronic Hardware Addendum, when specified) certified technicians. Quality control and PMP documentation ensure that all procedures are performed in sequence using the correct parts and materials. Metal materials are cleaned, prepared, and installed with strain gage elements, interconnections, and electronic circuits. Outgassing and cross-contamination from materials such as film, tape, adhesives, paint, coatings, primers, and potting compound are minimized by curing and drying steps.

To ensure each fabrication step is done correctly, work is inspected and/or electrically tested using measurements from calibrated automated instrumentation. Test data includes strain measurements (both zero and shunt), resistance, insulation resistance, voltage, and current. All data are recorded and stored for use in generating reports and for calculating adjustments. Adjustments in Gaging may include zero balancing, temperature drift compensation, and output signal trim.

Final testing includes both standard and specific test requirements. Specific test requirements may include items such as First Article Inspection, Dimensional Inspection, Cable Pull Tests, and Receptacle Mate/De-Mate Cycle Testing.

Marking and Packaging process

Prior to shipment all items are marked and packaged according to specific requirements. Each Force Transducer system will include identification markings, which may include labels, etchings, and engravings. Specific shipping container labels may also be generated. Reports, certificates, and other required documentation are made available to the customer and/or included within the packaging.

Please contact us to design a proven custom force sensor for your specific application.