Interface requirements for sensor-card contact-wear evaluation

System boundary

System motion command through carrier and wiper, contact surface, terminals, harness, acquisition and acceptance processing

Provide the true contact-motion record

Define contact coordinate, active stroke, direction, speeds, acceleration, reversals and dwell positions. Convert external shaft or slider motion through the actual linkage. Include tolerance, backlash and overtravel that affect the wiper even when the user command is unchanged.

Divide service into operating modes such as setup, normal control, calibration, vibration exposure and shutdown. Give occurrence and duration for each. A representative time series helps reveal short oscillations that a cycle total cannot preserve.

Summarize exposure by position bin

For each travel bin, report pass count, cumulative sliding distance, reversal count, dwell and associated environment. Highlight the most frequently crossed transition and the region with the longest stationary contact.

A simple distance measure is D_j=sum(n_k d_kj). If 4,000 motions each traverse 12 millimetres in bin j, the illustrative cumulative distance is 48,000 millimetres. Force and material effects remain separate; this arithmetic is not a life prediction.

Retain direction within the histogram because entering a region and leaving it may load contact fingers differently. Also distinguish travel under powered measurement from unpowered shipping, assembly or manual service movement. When field data are incomplete, state the observation window, sampling method and unobserved operating modes. A conservative duty assumption should be identified as an assumption and reviewed by the system owner rather than presented as measured service.

Define the installed contact pair

Provide wiper material, finish, number of fingers, footprint, approach angle, nominal force and allowed variation. Record card surface family, conductor transitions and any protected areas.

State mounting flatness, carrier alignment and deflection stack. Total spring load alone is insufficient when fingers share force unevenly. Identify who verifies the assembled force profile and when it is measured.

Name the environment that reaches the interface

List temperature range and transitions, humidity, condensation, dust, process vapor, lubricant, cleaning residue and enclosure ventilation. State which media can touch the contact directly and which are separated by seals.

Include assembly and maintenance exposures. Packaging powder, glove residue or a field cleaner can alter contact behavior even if normal service is nominally dry. Unknown chemistry should remain an open compatibility item.

Define allowable electrical events

Specify resistance change, interruption amplitude, minimum event duration, noise metric and position dependence at named terminals or controller nodes. State sampling and filtering used for acceptance.

An event absent from the displayed value may still exist at the contact. Preserve raw acquisition during evaluation and distinguish physical continuity requirements from software debounce or substitution.

Preserve evidence needed to separate causes

Relate every electrical anomaly to contact position, direction, speed, force state and environmental condition. Photograph mapped surface regions before cleaning and retain loose debris when practical.

Use controlled comparison rather than assuming every noisy trace is wear. Harness motion, acquisition limits and connector faults require independent checks.

Bound accelerated-test substitutions

State which variable is accelerated and why the same wear mechanism is expected. Higher speed, force, temperature or contaminant concentration may create a new mechanism rather than shorten the same process.

Preserve reversal and position distribution whenever localized exposure matters. Define inspection intervals, stop conditions and comparison specimens before the run. Do not extrapolate life without a supported model and application approval.

Compare wear location, debris character, surface appearance and electrical signature between representative-duty and accelerated groups. If acceleration moves damage from a reversal hotspot to an endpoint, changes transfer film, or produces a different interruption pattern, the equivalence argument has failed. Record fixture temperature, actual wiper coordinate and force state during the run; machine cycle commands alone do not prove that the intended contact exposure occurred.

Validate the complete observation path

Use representative card, wiper, carrier, mounting, harness and acquisition settings. Capture motion, force where required, terminal behavior, raw samples and processed output on a common time base.

Freeze acceptance metrics, uncertainty, invalid-run and retest rules. Report specimen history and any cleaning. Evidence applies to the tested duty and configuration; production or lifetime claims require separate substantiation.

Repeat observations at the declared reversal hotspot and at a lightly used reference region. This contrast helps distinguish localized contact evolution from global instrument drift or a controller-setting change.

Contact-wear evaluation should be organized by where motion occurs and how often each region is crossed. Build a position histogram from the intended duty cycle, then identify reversals, dwell zones and high-current switching events that may concentrate exposure. During testing, retain periodic full-stroke resistance traces in addition to the controller output. A local increase in noise near one position can otherwise disappear inside a single average value. Inspect the mating contact, preload mechanism and contamination controls at agreed intervals without changing them between electrical measurements. Acceleration factors require customer approval because speed, load, atmosphere and electrical bias can alter the damage mechanism. Service-life acceptance belongs to the complete sensor assembly and its mission profile.

Control changes that alter wear or visibility

Link stroke, control law, stops, spring, footprint, material, enclosure, cleaner, sample rate and filter revisions. Any can move a hotspot or hide an emerging event.

Review intermittent open, biased plausible output, debris migration and delayed detection separately. The system owner defines consequence and fallback. Unspecified service inputs must not be replaced with generic assumptions.

RFQ inputs for contact-wear evaluation

Submit contact travel, position histogram, reversals, dwell, speed, wiper geometry, load profile and materials. Include mounting, environment, cleaning and sealing.

Provide circuit nodes, event limits, bandwidth, filter, test duration, inspection plan, quantities and owners. Mark which evidence is required for development versus release acceptance.