Process Calibrators: Multifunction, Loop & Signal

Multifunction and loop calibrators for mA, voltage, thermocouple, RTD, frequency, and related process signals — Additel, PIE, and complementary tools, with ISO/IEC 17025 accredited calibration available on most instruments.

What a process calibrator does

A process calibrator sources and/or measures the electrical signals used in industrial control loops so you can check transmitters, I/O, and controllers without the full process running. Multifunction models combine several signal types in one handheld.

Common jobs

• 4–20 mA loops — source, simulate, and measure with or without loop power.
• Temperature signals — thermocouple and RTD simulate/measure for transmitter and control checks.
• Voltage / frequency — for a wide range of sensors and discrete checks.
• Diagnostics — leak/fault finding features on documenting models (including PIE diagnostic tools where offered).

Choosing a calibrator

• Signals required — mA-only vs multifunction (TC/RTD/V/Hz).
• Documenting vs basic — as-found/as-left storage and PC download.
• HART / fieldbus — only when your installed base needs it (check each model).
• Intrinsic safety when the area classification requires it.

Brands in this category

Additel documenting process calibrators, PIE handheld process calibrators (loop, TC, RTD, multifunction), and related accessories. Pressure work often pairs with our Pressure Calibrators and Gauges categories.

Popular process calibrators

• Multifunction — PIE 820, PIE 830, PIE 850, Additel 226, Additel 227 documenting, JOFRA ASC-400 and REED R5850.
• Loop (4–20 mA) — PIE 334, PIE 334Plus and REED R5825.
• RTD / thermocouple — see the PIE RTD and TC calibrators under temperature calibrators.

Multifunction process calibrators compared

The figures below come from each manufacturer's own product page, datasheet or selection guide. Check the full datasheet for the ranges and accuracy your procedure needs.

Additel 226: touchscreen multifunction calibrator

• Measures, sources and simulates pressure, temperature and electrical signals on a color touchscreen.
• Electrical accuracy: 0.015% RDG + 0.005% FS (Additel).
• Built-in barometer, dual-channel pressure module ports, and a high-static differential pressure mode to 0.002% FS.
• USB Type-C and Bluetooth, IP67 rating, 300 V AC true-RMS voltage measurement. The ADT226Ex is an ATEX intrinsically safe version.
• No HART communicator (a HART 250 Ω resistor adapter is offered). View the Additel 226

Additel 227: documenting, with an optional full HART communicator

• Same platform as the 226, with a tighter electrical accuracy of 0.005% RDG + 0.005% FS (Additel).
• Adds automated task management (documenting) and datalogging.
• The ADT227-HART adds a full HART communicator. The ADT227Ex is an ATEX intrinsically safe version. View the Additel 227

JOFRA ASC-400: keypad calibrator that pairs with APM pressure modules

• Reads and sources RTD, thermocouple, current, voltage, frequency and resistance, and sources pulse trains.
• Isolated read-back with simultaneous input and output, so you can calibrate a transmitter with no extra equipment.
• With a JOFRA APM pressure module it becomes a pressure calibrator (vacuum to 1000 bar / 15,000 psi, accuracy down to 0.025% RDG) with leak and switch tests.
• RTD characterization (Callendar-Van Dusen) and "true ohm" technology for reference thermometer use. Full-color display, numeric keypad, built-in connection assistant and fuseless protection. View the JOFRA ASC-400

PIE 820: pocket-size multifunction calibrator

• Sources 0 to 24 mA, 0 to 10.25 VDC and 0 to 80 mV. Reads up to 60 VDC.
• Built-in 24 V loop supply and a 250 Ω resistor for HART hook-ups.
• 14 thermocouple types (J, K, T, E, R, S, B, N, G, C, D, L, U, P), plus Pt100/Pt1000, copper and nickel RTDs.
• Frequency to 20 kHz, and a continuity checker. View the PIE 820

PIE 830: dual-channel diagnostic calibrator

• Dual channels covering mA, V, TC, ohms, RTD, Hz, pH and pressure.
• Patented loop diagnostics detect ground faults and current leakage. LoopScope shows loop current, voltage and resistance at once.
• Automatically detects 2-, 3- and 4-wire RTDs, and can stand in as a universal isolated transmitter for temperature, frequency, millivolt or pressure. View the PIE 830

PIE 850: for 10–50 mA systems

• Sources 0 to 24 mA and 0 to 50 mA. Reads to 52 mA, 60 VDC and ±999.99 mV.
• Loop power of 24 VDC at 20 mA or 40 VDC at 50 mA, plus a 250 Ω HART resistor.
• Loop diagnostics and LoopScope, with pH and pressure functions. View the PIE 850

Which one fits

• HART communication built in: Additel 227-HART.
• Documenting and task management: Additel 227.
• Hazardous (ATEX) areas: Additel 226Ex or 227Ex.
• Pressure plus signals in one kit: JOFRA ASC-400 with an APM module, or an Additel 226/227 with its pressure module ports.
• Pocket-size loop troubleshooting: PIE 820, or the PIE 830 for diagnostics and dual channels.
• Legacy 10–50 mA loops: PIE 850.

More models in this category

• Crystal FastCalXP: gauge and transmitter calibration software.
• JOFRA ASM Advanced Signal Multi-scanner: eight-channel advanced process multi-scanner for automated calibration of multiple pressure and temperature sensors.
• PIE 235 Process Voltage Calibrator
• PIE 525Plus Diagnostic TC, RTD and mA Calibrator: diagnostic thermocouple, RTD, and milliamp calibrator.
• PIE 541 Frequency Calibrator: frequency calibrator for Hz, kHz, CPM, and pulse applications.
• PIE 820 Elite Multifunction Diagnostic Calibrator
• PIE 820PM Panel Mount Multifunction Calibrator
• PIE 830PM Panel Mount Multifunction Calibrator
• PIE 901 Wireless Diagnostic Calibrator
• Ralston FieldLab Digital Pressure Calibrator
• Ralston FieldLab Hydrostatic Test Kits: FieldLab FLHT hydrostatic test kits with wireless pressure recording.
• REED R5805 Voltage/Current Simulator: sources DC voltage and current.

Frequently asked questions

Which process calibrator has HART communication built in?

The Additel 227-HART.

Which process calibrators are rated for hazardous areas?

The Additel 226Ex and 227Ex are the ATEX versions.

Can one calibrator handle pressure and electrical signals?

Yes. The JOFRA ASC-400 accepts APM pressure modules, and the Additel 226 and 227 have pressure module ports.

What should I use for pocket-size loop troubleshooting?

The PIE 820, or the PIE 830 when you need diagnostics and dual channels. For legacy 10–50 mA loops, use the PIE 850.

Calibration

Most process calibrators can ship with ISO/IEC 17025 accredited calibration. Tell us which functions and ranges matter for your procedure.