Does the lab replace a loop calibrator?

No. It teaches calculation, diagnosis and evidence structure. Physical calibration still requires an appropriate reference instrument, isolation procedure and the manufacturer’s instructions.

Can I use negative engineering ranges?

Yes. The linear formula works with ranges such as −50 to 150 °C as long as the minimum and maximum are not equal.

Does the lab replace a loop calibrator?

No. It teaches calculation, diagnosis and evidence structure. Physical calibration still requires an appropriate reference instrument, isolation procedure and the manufacturer’s instructions.

Can I use negative engineering ranges?

Yes. The linear formula works with ranges such as −50 to 150 °C as long as the minimum and maximum are not equal.

PLC Simulator

Calibration and signal lab

Instrumentation Simulator: 4–20 mA Signal & Fault Lab

Scale a real 4–20 mA signal, diagnose a broken loop and build calibration evidence before working on live process instrumentation.

Run before signup Server-graded Save, share and fork

Open the workbench

industrial-lab / instrumentation

MODETRAINING

GRADERSERVER AUTHORITY

EVIDENCECHECKS + SCORE

First challenge

Scale a 4–20 mA transmitter

Convert a loop current into engineering units for a configurable transmitter range.

Reusable lab resources

Calibration record templateCSV

Recognise the complete signal path

From field transmitter to a trustworthy PLC value.

A current-loop calculation only becomes useful when you can connect it to the power supply, instrument, input channel, engineering range and process response. These six views follow that workflow from the bench to the plant.

Pressure transmitter connected to a 24 VDC 4–20 mA loop and calibrated loop meter — 01Read the loop as a circuit: the transmitter regulates current, the 24 VDC supply provides loop power and the meter is placed in series for a current measurement.

Instrumentation technician calibrating transmitter zero and span with a hand pump and reference gauge — 02Apply known reference points, compare as-found readings, adjust only when authorised and record the as-left result.

PLC analog input module wired for 4–20 mA with an engineering-unit scaling worksheet — 03Match the channel mode and raw range to the module, then scale the signal into pressure, temperature, flow or level units.

Safe terminal-block multimeter test diagnosing an open 4–20 mA instrument loop — 04A near-zero reading can indicate lost loop power or an open circuit. Prove supply, polarity, continuity and channel configuration before changing code.

RTD temperature sensor and head transmitter being checked with a process calibrator — 05Separate the sensing element from the transmitter: an RTD changes resistance, while the transmitter converts that measurement into the loop signal.

Process skid with tank, control valve, pressure transmitter and live trend display — 06Close the loop by checking whether the scaled PLC value agrees with the process, alarms and operator trend—not merely the current at one terminal.

Interactive calibration lab

Configure. Run. Read the evidence.

Foundation

Scale a 4–20 mA transmitter

Convert a loop current into engineering units for a configurable transmitter range.

Loop current (mA)Range minimumRange maximumCalculated engineering value

Evidence appears here

The backend calculates the expected result and returns individual checks, a score and reproducible evidence. Client-supplied scores are ignored.

Your run is free. Keep the evidence when it matters.

Create an account only when you want saved attempts, projects, sharing and progress.

Save this result

Training outcomes

More than a calculator.

Each run teaches a transferable industrial workflow and produces evidence you can inspect, repeat and discuss.

Convert loop current into pressure, temperature, flow or level units.

Explain live zero and separate a true zero measurement from a broken loop.

Build a repeatable calibration record with objective grading.

Move directly into PLC analog-I/O and process-control scenarios.

Field method

How to reason through the lab

STEP 01

Prove the loop before scaling

Confirm supply, polarity, series connection and input-card mode. A perfect scaling equation cannot fix an open loop or a voltage input configured for current.

STEP 02

Calculate percent of span

For a standard loop, percent span is (mA − 4) ÷ 16. Multiply that fraction by the engineering span and add the engineering minimum.

STEP 03

Record as-found and as-left evidence

A defensible calibration records the test points, reference standard, tolerance, adjustment and final result—not just a pass tick.

Continue from a single exercise to a complete training record.

Guided scenarios, saved progress, fault diagnosis and instructor reporting are built into the main platform.

Compare training plans

Technical practice library

Load a real job, not an empty calculator.

Each reference explains a distinct industrial task and links back to an exact grader preset with server-owned acceptance evidence.

Browse all training exercises

Gauge pressure transmitter

Scale a 4–20 mA Pressure Transmitter: 0–10 bar

Calculate and grade a 0–10 bar pressure-transmitter signal at 12 mA, then record the calibration evidence and live-zero checks.

Method Load preset →

RTD temperature transmitter

Scale a 4–20 mA Temperature Transmitter: −50 to 150 °C

Work a bipolar temperature-transmitter scaling example at 8 mA and verify the result in a server-graded instrumentation lab.

Method Load preset →

Hydrostatic level transmitter

Scale a 4–20 mA Tank Level Transmitter: 0–5 m

Convert a 16 mA level signal into metres, verify 75% span and carry the evidence into the instrumentation simulator.

Method Load preset →

Magnetic flow transmitter

Scale a 4–20 mA Flow Transmitter: 0–200 m³/h

Calculate an 80 m³/h flow indication from 10.4 mA and validate the linear scaling in the browser lab.

Method Load preset →

Control-valve position transmitter

Scale a 4–20 mA Valve Position Feedback Signal

Translate 18.4 mA into 90% valve travel and separate feedback scaling from the output command.

Method Load preset →

Vacuum pressure transmitter

Scale a Vacuum Transmitter: −100 to 0 kPa

Solve a negative-range 4–20 mA vacuum-transmitter example at 6.4 mA and verify the −85 kPa result with graded evidence.

Method Load preset →

Low-range differential-pressure transmitter

Scale a Differential-Pressure Transmitter: 0–250 Pa

Calculate a 160 Pa filter differential from 14.24 mA and verify the air-handler alarm input scaling in the graded lab.

Method Load preset →

Conductivity transmitter

Scale a Conductivity Transmitter: 0–20 mS/cm

Convert 7.2 mA into 4 mS/cm and validate the analogue scaling used by a water-quality interlock.

Method Load preset →

Technical review

Primary references used for this lab

Reviewed 7 August 2026. The simulator teaches a repeatable training method; always use the exact module and instrument manuals for live commissioning work.

Instrumentation Simulator: 4–20 mA Signal & Fault Lab questions

What learners and instructors ask.

The 4 mA live zero allows the receiver to distinguish a valid zero measurement from a broken wire or lost transmitter power near 0 mA.