Retention accuracy testing service

Retention Accuracy Testing Service – Accredited Evaluation of Dimensional, Pressure, Temperature, and Performance Stability

For Brazilian manufacturers, importers, and quality engineers in the automotive, aerospace, medical device, oil & gas, and industrial equipment sectors, the ability of a product, component, or system to maintain its specified performance parameters over time – under varying environmental conditions, load cycles, and operational stresses – is a critical reliability and safety attribute. Retention accuracy, defined as the capability to preserve key characteristics such as dimensional tolerances, pressure‑holding capacity, temperature stability, speed accuracy, and flow rate consistency, is fundamental for ensuring that products perform as intended throughout their service life. Our ISO/IEC 17025 accredited laboratory offers a specialised retention accuracy testing service that quantifies the stability, drift, repeatability, and long‑term performance of a wide range of components and systems, using precision measurement instruments, environmental chambers, pressure and temperature controllers, and automated data acquisition systems, in full compliance with ABNT NBR, ISO, IEC, ASTM, and customer‑specific specifications. With decades of experience in performance characterisation and reliability engineering, we provide precise, repeatable, and fully documented test results that are accepted by INMETRO, ANVISA, and Brazilian certification bodies, supporting your product approval, quality assurance, and regulatory compliance.

Products and Components We Regularly Test

We accept a wide variety of products, sub‑assemblies, and systems that require verification of their ability to maintain performance accuracy over time. Our test setups are adaptable to different sizes, pressure ratings, temperature ranges, and operating conditions. Common samples include:

• Pressure regulators and relief valves – for gas, hydraulic, and pneumatic systems.
• Temperature controllers and thermostats – for HVAC, industrial heating, and refrigeration.
• Flow meters and flow regulators – for liquids and gases, including mass flow and volumetric types.
• Speed sensors and tachometers – for motor, pump, and conveyor speed monitoring.
• Position encoders and linear transducers – for precise motion control.
• Timing devices and delay relays – for sequence control and safety applications.
• Load cells and force sensors – for weighing and force measurement systems.
• Pressure sensors and transmitters – for process control and monitoring.
• Complete control systems – for testing the accuracy of integrated loops and feedback systems.

Core Test Methods – Accuracy, Drift, Repeatability, and Stability

Our retention accuracy testing service uses a combination of standardised and customised test methods to characterise the long‑term stability and performance retention of components and systems. The selection of tests depends on the product type, the critical parameters to be controlled, and the operating environment:

• Dimensional retention test (ISO 1101, ABNT NBR ISO 1101, and ASME Y14.5) – We measure the dimensional accuracy of a component (e.g., machined part, moulded part, or assembly) and then subject it to a defined number of operational cycles, temperature variations, or load conditions. We re‑measure the dimensions to evaluate the change (drift) from the initial value. The retention accuracy is expressed as the absolute deviation or as a percentage of the nominal dimension. This test is critical for moving parts, sealing surfaces, and precision‑fit components.
• Pressure retention test (ISO 15360, ASME BPVC, and ABNT NBR 15884) – We pressurise the device to a specified set point (or to the rated pressure) and monitor the pressure‑holding capability over a defined time period (typically 24, 72, or 168 hours). We record any pressure drop, drift, or instability, and we evaluate the device’s ability to maintain the pressure within the specified tolerance. This test is essential for valves, regulators, cylinders, and accumulators.
• Temperature retention test (IEC 60068‑2‑1, IEC 60068‑2‑2, and ABNT NBR IEC 60068‑2‑1/2‑2) – We condition the device at a set temperature and measure its ability to maintain the temperature within a defined band. We then cycle the device between low and high temperatures (e.g., -40°C to +85°C) and measure the temperature retention accuracy (the deviation from the set point) at each step. This is used for thermostats, temperature controllers, and thermal management systems.
• Speed retention test (ISO 15086‑1, SAE J1939, and customer‑specific specifications) – For motors, drives, and speed sensors, we apply a controlled load and measure the speed output. We then subject the device to a prolonged run‑time or cyclic loading and re‑measure the speed to evaluate the retention of the speed accuracy. The drift is expressed as a percentage of the nominal speed.
• Flow retention test (ISO 5167, ASME MFC‑7M, and ABNT NBR 14468) – For flow meters and regulators, we apply a controlled flow rate and measure the output. We then run the device for a specified period (or a number of cycles) and re‑test the flow rate. The deviation from the initial calibration value is reported as the flow retention accuracy.
• Position retention test (ISO 9283, VDI/VDE 2634, and ANSI/BIFMA X5.1) – For actuators, robotic arms, and positioning tables, we measure the position accuracy and repeatability, then cycle the actuator through a defined number of motions. We re‑measure the position accuracy to evaluate the retention of the positioning capability, which is critical for CNC machines, robotics, and automation equipment.
• Time retention test (IEC 60947‑5‑1, EN 60062, and NBR 14136) – For timing relays and delay devices, we measure the set timing accuracy and then run the device through a specified number of operations (or a period of continuous operation). We re‑measure the timing accuracy to evaluate the retention of the time setting, which is essential for safety‑critical timing functions.
• Load cell and force sensor retention test (ASTM E74, ISO 7500‑1, and ABNT NBR ISO 7500‑1) – We apply a defined force to a load cell and record the output. Then we subject the load cell to a given number of loading cycles (or to a temperature or humidity cycle) and re‑test the force output to evaluate the retention of the load cell’s calibration accuracy.
• Combined retention test – we combine multiple stress factors (e.g., pressure + temperature, load + temperature, speed + vibration) to simulate the most realistic service conditions – This provides a more comprehensive assessment of the product’s ability to retain accuracy under the actual operating environment.

Test Set‑up, Instrumentation, and Data Acquisition

Accurate retention testing requires precise control of the test variables and high‑quality measurement systems. Our laboratories are equipped with state‑of‑the‑art instrumentation for pressure, temperature, flow, speed, and position measurement:

• Pressure controllers and transducers – we use precision pressure controllers (accuracy < 0.1% of full scale) and pressure transducers (class 0.05) to apply and measure pressure, with traceability to Inmetro – The pressure is controlled to within ±0.1 bar for typical ranges.
• Temperature controllers and sensors – we use programmable temperature chambers with accuracy < 0.5°C, and we use PT100 resistance thermometers with an uncertainty of ±0.1°C to monitor the test temperature – The chambers can be programmed with ramp‑and‑soak profiles to simulate thermal cycles.
• Flow meters and flow controllers – we use calibrated flow meters (turbine, thermal, or ultrasonic) with an accuracy of < 1% of reading, and we use feedback controllers to maintain the flow rate within the specified tolerance – The flow rate is recorded continuously.
• Speed and torque sensors – we use high‑accuracy tachometers and torque meters (accuracy < 0.1%) to monitor the rotational speed and torque, with direct traceability to national standards – The sensors are verified with a reference standard before each test.
• Position and displacement sensors – we use linear variable differential transformers (LVDTs) with accuracy < 0.01 mm, and laser displacement sensors, to measure the position and displacement of moving parts – The sensors are calibrated with a gauge block.
• Data acquisition system – we use a high‑speed, multi‑channel data acquisition system that records all measurement parameters (pressure, temperature, flow, speed, position, time) simultaneously, ensuring that all data is synchronised and traceable – The system is set to record at defined intervals (e.g., 1 second, 10 seconds, or 1 minute) depending on the test duration.

Evaluation Criteria and Interpretation of Results

Based on the measured data, our specialists evaluate the performance of the component or system and provide a clear conclusion on the retention accuracy. The interpretation includes:

• Determination of the drift value – the difference between the measured value (at the end of the test) and the reference value (the initial measurement or the set point), expressed in the same unit – We calculate the drift as an absolute value or as a percentage of the nominal value.
• Comparison with the specified tolerance – we compare the measured drift with the acceptance tolerance (e.g., ±1%, ±0.5%, ±0.1°C, ±0.5 bar) and issue a pass/fail conclusion – We also provide a detailed explanation of the results.
• Analysis of the stability – we evaluate the trend of the measured parameter over time, identifying any drift, oscillation, or instability that may indicate a design or material issue – We provide graphs of the parameter versus time.
• Identification of root causes – if the product fails to retain accuracy, we investigate possible causes such as thermal expansion, mechanical wear, seal relaxation, material fatigue, or electronic drift – We provide recommendations for design modifications, material changes, or calibration adjustments.
• Recommendations for improvement – we provide actionable recommendations to improve the retention accuracy, such as using more stable materials, improving the sealing design, or adding compensation circuits – We also advise on the optimal maintenance intervals.

Environmental and Operational Conditioning

Retention accuracy can be affected by temperature, humidity, vibration, and aging. We offer conditioning options to simulate the real‑world environment:

• Temperature cycling – we pre‑condition the device through a number of temperature cycles (e.g., -40°C to +85°C) before the retention test, to simulate the effect of thermal expansion and contraction on the accuracy – This is essential for electronic devices and pressure‑containing components.
• Humidity conditioning – we expose the device to high‑humidity environments (up to 95% RH) for a specified period, to simulate the effect of moisture on the electrical and mechanical properties – This is important for electronics and for components that are sealed but may be subject to condensation.
• Vibration conditioning – we apply controlled vibration (sinusoidal or random) to the device during the retention test, to simulate the effect of machinery or transport vibration – This is relevant for automotive and aerospace components.
• Pressure cycling – we apply a defined number of pressure cycles (e.g., 10,000 cycles) to the device before the retention test, to simulate the effect of repeated pressure stress on the pressure‑holding capability – This is used for regulators, valves, and seals.

Compliance with Brazilian and International Standards

Our retention accuracy testing services support compliance with the key standards for performance, safety, and reliability:

• ABNT NBR ISO 1101 (Geometrical Product Specifications – Tolerances of form, orientation, location and run‑out) – For dimensional retention.
• ISO 15360 (Hydraulic fluid power – Cyclic pressure testing) – For pressure retention and pressure cycling.
• IEC 60068‑2‑14 (Environmental testing – Temperature cycling) – For temperature retention and thermal cycling.
• ISO 15086‑1 (Hydraulic fluid power – Determination of flow rate characteristics of components) – For flow retention.
• ASTM E74 (Calibration of force‑measuring instruments) – For load cell retention.
• INMETRO Ordinance 553/2021 and PROCEL requirements – for efficiency and performance retention – Our reports are accepted for product certification.
• Customer‑specific requirements – we can adapt our test procedures to meet the specific performance criteria of automotive, aerospace, and medical device manufacturers – Our reports are accepted by major Brazilian and multinational companies.

Reporting and Accreditation

All retention accuracy tests are performed under our ISO/IEC 17025 accredited quality system, with full traceability of all measurement parameters. Our Inmetro‑accredited reports are recognised by INMETRO, ANVISA, and various Brazilian certification bodies. Each report includes:

• A complete description of the product or component (model, serial number, specifications, and configuration).
• Detailed test conditions (temperature, pressure, flow, speed, and conditioning cycles).
• Measured values (initial reference, final measurement, and drift) for each parameter.
• Comparison with the specified tolerance and a clear pass/fail conclusion.
• Graphs of the measured parameter over time, showing the stability and drift.
• Calibration certificates for all test equipment and measurement uncertainty statements.
• Recommendations for design improvement, if necessary.

Our reports provide the confidence you need to certify your products, approve deliveries, and ensure that your components and systems can maintain their accuracy throughout their service life.

Why Choose Our Retention Accuracy Testing Service?

We understand that the ability of a product to maintain its performance over time is essential for safety, reliability, and customer satisfaction. Our team offers rapid scheduling, flexible test programmes (from simple drift measurements to complex multi‑factor cyclic studies), and clear, actionable interpretation of results – we do not just give you a pass/fail; we explain the root causes of any degradation, the implications for your system, and the steps you can take to improve retention. We work closely with your design, quality, and maintenance teams to select the appropriate test parameters, conditioning regimes, and acceptance criteria for your specific product and application. With high‑precision measurement equipment, environmental chambers, and a highly experienced team, our retention accuracy testing service delivers the accuracy, repeatability, and regulatory acceptance you need to ensure that your products perform reliably and consistently. Contact us to discuss your retention requirements – we will develop a customised test programme that provides the definitive evidence of your product’s performance stability.