Accuracy and Calibration of Digital, Dial, and Vernier Calipers

the accuracy and calibration of digital, dial, and vernier calipers, based on the American national standard ASME B89.1.14-2018. It emphasizes the importance of calibration and verification to ensure accuracy. The bulletin also mentions the need for a reference standard for inside measurements and the availability of accredited calibrations and measurement standards.

What is calibration

Metrology has created a unit to clarify calibration concepts, based on ASME B89.7.1-2016, Guidelines for Addressing Measurement Uncertainty. The unit aims to clarify the connection between quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties. Calibration involves relating measured values from measuring equipment to those from calibrated measurement standards, enabling units of measurement on equipment to be traced back to an official reference. Calibration measurements have three purposes: determining reference values, determining test values for verification to tolerance, and determining necessary adjustments to measuring equipment. Clear expectations and careful usage of the word "calibration" when requesting calibration services can help avoid confusion.

Decision Rules, TAR and TUR

Decision rules, such as the simple acceptance and rejection decision rule, are crucial in measuring accuracy and uncertainty. The simple acceptance and rejection rule, based on ANSI standards, is used in almost all situations, with measured values within tolerance limits considered acceptable. The Test Accuracy Ratio (TAR) is a related measure of risk in measurement systems. The evaluation of measurement uncertainty became more prevalent in commercial calibration practice in the late 1990s, leading to the replacement of TAR with the test uncertainty ratio (TUR). Both TAR and TUR can be useful in measurement practice, with TUR useful in selecting calibration providers and TAR useful in selecting new measuring equipment.

SF6 Leak Pointer Repair at Eurocaltech

SF6 Leak Pointer RepairThe SF6 Leak Pointer is a lightweight, cordless device that can detect SF6 leaks in seven sensitivity levels with a response rate of less than one second

SF6 Gas Handler Fittings

Eurocaltech offers SF6 gas handler fittings such as compression, flange, flare, and NPT. They also provide couplings and valves for alternative gases like C4-FN, C5-FK, and DILO Couplings CA. These connections are pressure-tight and have leak rates less than 1x10-8 mbar l/s. Eurocaltech also provides f adapter kits for common connections, such as the DN8 Testing and Filling Adapter Kit and the DN20 V3 Adapter Kit. With over several years of experience, Eurocaltech is a trusted choice for expert gas handling.

SF6 Gas Hazards and Solutions

SF6 gas, a crucial insulator in electrical equipment, poses health hazards due to its asphyxiant nature. It's one of six greenhouse gases contributing to climate change. Common hazards include oxygen displacement and malfunctions. Businesses should establish robust monitoring programs and evacuate personnel in case of exposure

SF6 GAS HANDLING

SF6 gas, a potent greenhouse gas, can remain in the atmosphere for over 3,000 years if released. Proper gas handling practices are crucial to minimize emissions. Eurocaltech offers training sessions and onsite support for gas-insulated equipment (GIE) handling. Pro tips include relieving pressure before disconnecting, following proper start-up procedures, preparing equipment, recovering gas on failed breaker, checking filters, testing SF6 cylinders, and using nitrogen to rinse recovery systems. Proper PPE and neutralization of disposal items are also essential.

Temperature Sensors and Calibration

Temperature is a derived metrology that requires indirect measurement. Types of thermometers include Liquid in Glass (LIG) thermometers, resistance thermometers, and voltage difference from a thermocouple. Sensor selection depends on temperature range, physical construction, and sensing length. Calibration involves comparing sensors to other thermometers or fixed points.

immersion Depth of the sensor PRT, SPRT, Thermocouple

Sensor immersion depth affects temperature measurement accuracy, with Dry Blocks having good uniformity over the bottom 40mm pocket. Calibration depends on application, sensors, temperature range, and accuracy requirements.

Water, Ice and the Triple Point

Water, a dense substance, is the primary source of Earth's water, with its density at +4°C. Ice, less dense, floats under water, and water supercools. The water triple point, a mixture of ice/water and water vapor, has a temperature of 0.01°C. This temperature is crucial for international temperature measurement standards and was developed by John Stimson.

Why Use a Standard Platinum Resistance Thermometer (SPRT)?

The Industrial Platinum Resistance Thermometer (IPRT) is a reliable standard for temperature measurement and calibration. It has a resistance of 100 Ohms and is metal sheathed. IPRTs can be calibrated with uncertainties of 0.01 °C and 0.05 °C, making them suitable for many applications. Primary SPRTs can be calibrated to lower uncertainties, while secondary SPRTs are less prone to mechanical shock. Eurocaltech offers high-accuracy precision thermometers with one-year accuracy. To make the best measurements with SPRTs, use a thermometry bridge.

Platinum Resistance Thermometers

Platinum resistance thermometers use ceramic sensing elements with thin wire coils to prevent shorting during heating or cooling. Ohm's law calculates resistance, measured using temperature equipment. Variables like current size, nominal resistance, thermometer design, and thermal contact affect self-heating.

Platinum Resistance Thermometer: Self Heating

Platinum resistance thermometers use a ceramic sensing element with fine platinum wire coils to measure resistance. Resistance is calculated using ohms law, with self-heating effect affecting the temperature due to the environment. The magnitude of self-heating depends on factors like current size, nominal resistance, thermometer construction, and thermal contact with the environment.

Thermocouple compensating cables

A thermocouple is a device with two wires of different metals welded together, insulated with PTFE, ceramic, or MIMS. It generates an output when a temperature gradient exists. Cold Junction Compensation (CJC) is used to compensate for the error in measured temperature by the equivalent of ambient temperature. A Double Junction Thermocouple (DJT) provides a test thermocouple with a Reference Junction (RJ) which is more accurate than using an electronic internal CJC system. The DJT can be switched on or off depending on whether the thermocouple is fitted with its own RJ, making it ideal for accurate thermocouple measurement.

BW sensors repair in UAE

Catalytic diffusion sensors detect combustible gases and vapors by wounding wire into coils doped with catalysts. They are intrinsically safe and display gas concentration in parts per million (PPM) and percent volume (%). Electrochemical sensors detect and amplify current causing gas diffusion. Pressure gauges should be compatible and managed through standardization, audits, and employee training.

Mud pressure gauge repair

Pressure gauge failure is a critical issue in production facilities, causing accidents and serious consequences. The top eight causes include extreme temperature, overpressure, mechanical vibration, corrosion, misuse, pulsation, clogging, and steam. To avoid overpressure issues, choose gauges with a pressure range greater than the designed overpressure or consider overload stops or vacuum stops. Corrosion should be made from compatible materials or fitted with a diaphragm seal. Misuse, pulsation, and clogging can cause damage. Proper management of pressure gauges can reduce downtime, promote safety, and boost profits.

Gauge,Absolute and Differential Pressure Measurement

Pressure measurements are essential for various applications, including high-accuracy vacuum measurements, distillation vacuum columns, and tank leakage checks. Absolute pressure serves as the base reference, while gauge pressure is the difference between atmospheric pressure and absolute pressure. Differential pressure is the difference between two points of pressure, used in level measurement, overpressure measurement, flow and filtration, and leak detection. Measuring units include BAR, PSI, PA, Torr, InHg, and InH2O. Absolute pressure gauges are sealed instruments that measure the actual pressure applied regardless of atmospheric pressure change. Differential pressure measurement measures pressure drop across a system, such as monitoring a filtration system within a pipeline.

Digital pressure gauges repair

Digital pressure gauges are microprocessor-controlled devices used in various industries, including pharmaceuticals, food processing, petrochemicals, and water. They offer long calibration, better performance in extreme vibration, clear readings, customizable settings, and data logs. However, they require a power source, are expensive, require special certifications, and may need frequent calibration. They can be used with hydraulic and pneumatic comparators for higher accuracy.

Dead weight tester repair

Eurocaltech offers repair and refurbishment services for pressure gauges, valves, and Dead Weight Testers in high temperature or corrosive environments. Diaphragm seals can be repaired or replaced using welded or clamped seals. Regular checks and calibration are necessary for safety and efficiency in industrial facilities.

Wika Pressure and Temperature Gauges repair

Pressure and temperature gauges are crucial tools in the oil and gas industry, used for extracting, transporting, and refining natural raw materials. They are used in drilling, transportation, storage, refinery, and petrochemical industries. Standpipe pressure gauges are used for standpipes, choke manifolds, pump trucks, and mud pumps, while gas-filled thermometers are used in harsh offshore environments. Differential pressure gauges are used for monitoring levels and pressures within storage tanks, while pressure measuring instruments are used in refineries for processes like distillation, fractionation, hydrocracking, process treatment, biodiesel, and ethanol production. Euro Caltech offers a wide range of pressure gauges, including standard full SS, solid front full SS, phenol case, SS case brass, low pressure diphragm, electric contact standard full SS, differential pressure gauges, and piston operated differential pressure gauges.

Standard vs Accredited Calibration

Choosing an accredited calibration provider is crucial for equipment accuracy and reliability. Non-accredited labs lack quality systems and follow technical regulations. Accredited laboratories, governed by ISO/IEC 17025, undergo regular audits. Accredited calibration helps minimize risk from out-of-tolerance instruments.

calibration standards

Calibration standards verify device performance, facilitate traceability, and facilitate international trade. They are found in primary calibration laboratories, often National Metrology Institutes, accredited by independent organizations.