Digital Pressure Calibrator

What is the Digital Pressure Calibrator?

A portable instrument with an internal pressure sensor and often a hand pump that generates and measures pressure to calibrate gauges, transmitters and switches. It is the right choice for checking process instruments on site or in a lab.

Overview

A digital pressure calibrator combines a reference pressure sensor with a pressure source, typically a hand pump or screw press, and electrical measurement of 4 to 20 mA, voltage and switch states. Piezoresistive silicon sensors provide accuracy between 0.025 and 0.05 percent of full scale across ranges from 10 kPa vacuum to 70 MPa. Some models have replaceable external pressure modules so one handheld device can cover multiple ranges. A loop power supply of 24 V DC allows testing of transmitters, and HART communication allows configuration. The calibrator records as-found and as-left data, calculates error, and documents results on a certificate. Accuracy depends on temperature compensation, zero stability and orientation of the sensor, and the reference should be calibrated at least annually.

How does it work?

A measurement system converts a physical variable into an electrical signal with a sensor, conditions and digitizes that signal, applies calibration coefficients and displays or records the result. Electromagnetic force restoration balances compensate the load with a current through a coil. Strain-gauge or piezoresistive sensors turn pressure and force into bridge voltages. Platinum resistance thermometers and thermocouples produce resistance or voltage that varies with temperature. Capacitive polymer sensors change capacitance with relative humidity. The system accuracy combines sensor quality, amplifier stability, analog-to-digital resolution, temperature effects and calibration uncertainty. Traceability to national standards is established by periodic calibration with higher-accuracy references. Data loggers and software add time-stamped records, limit alarms and statistical analysis for quality documentation.

What are the key features?

• Piezoresistive reference sensor reaches 0.025 percent of full scale accuracy.
• Interchangeable pressure modules cover vacuum to 70 MPa with one handheld unit.
• Integrated 24 V loop supply and mA measurement test transmitters in place.
• Documenting function records as-found and as-left data for calibration certificates.
• Hand pump with fine adjustment generates stable test pressure quickly.
• Rugged case and rechargeable battery support field use in plants.

What are the technical specifications?

A typical digital pressure calibrator configuration offers pressure range of −100 kPa to 70 MPa (by module), accuracy of ±0.025–0.05 % FS, resolution of 5 digits, electrical measurement of 0–24 mA, 0–30 V, loop power supply of 24 V DC and units of kPa, bar, psi, mmHg, etc.. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Digital Pressure Calibrator is used in calibration of pressure transmitters, gauge and switch verification, leak and pressure decay tests and vacuum system checks. Across the wider Measurement Systems class, laboratories also deploy it for formulation and sample weighing, calibration of process gauges and storage and cold chain monitoring.

Which standards and certifications apply?

Relevant standards and methods include ISO/IEC 17025, ISO 10012, OIML R 76-1, OIML R 111-1, EURAMET cg-18, IEC 60751, ISO 7500-1 and JJG 1036. Certification candidates for this model are CE, ISO 9001 manufacturing and ISO/IEC 17025 calibration certificate available; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Install measurement systems in a stable environment appropriate to their accuracy class. Balances need a vibration-free table, level mounting and protection from drafts and temperature swings. Allow warm-up before use. Verify each instrument with check weights or reference devices on a routine schedule, and send it for full calibration at intervals defined by your quality system, typically annually. Keep calibration certificates, as-found and as-left data and uncertainty budgets. Protect sensors from overload, shock and incompatible media. Label instruments with calibration status and due dates, and remove those out of tolerance from service. Train operators on correct handling, such as using tweezers for weights and stabilizing before reading.

How do I select the right Digital Pressure Calibrator?

Choose a digital pressure calibrator for field and lab verification of gauges and transmitters where the reference must be at least four times better than the device under test. Choose a deadweight tester for primary standards. In an RFQ specify pressure ranges, accuracy, media, connection type, electrical measurement needs, HART support and calibration certificate requirements.

How does it compare with other Measurement Systems variants?

Select the system by the variable, range and tolerance to be verified. Specify the resolution and accuracy needed at the working point, not only the full-scale value, and keep the instrument uncertainty to about one tenth to one third of the tolerance. For weighing, consider readability, capacity, repeatability and draft control. For pressure and temperature, check sensor type, media compatibility and environmental conditions. For monitoring, consider number of channels, logging interval, alarms and software features for audit trails. Confirm that calibration certificates are traceable and that calibration can be performed locally. Also consider ruggedness, battery life, display readability, connectivity and the ability to export data for regulatory or customer audits.