C75 Portable Multifunction Calibrator with Memory and Optional Pressure


The Wahl C75 Calibrator integrates all the necessary functions for calibration and maintenance of processes, making it an ideal instrument for maintenance, quality control, and calibration.  With ergonomic design and embedded software, the C75 is an easy-to-use, high performance calibrator.

The C75 is capable of simultaneously measuring and generating voltage, current, frequency, resistance signals, resistive probes, and thermocouples - on two isolated channels. Wide, high contrast backlit display is excellent for use in low ambient light conditions.

Add the optional absolute or relative external pressure modules (sold separately) to add pressure to your list of measurements.  Optional external pressure modules are digital and connected through a RS485 cable to the digital input corrector.  All data is digital. Measurements are compensated in temperature due to a polynomial correction implemented into the EEPROM at the factory.

Record data automatically or on user request. 10,000 data can be stored and displayed on the screen as a curve or list.

The unit is rated IP54 and protected by an anti-shock boot.  Polycarbonate keypad protects the unit from dirt and grease, and the raised keys allow the C75 to be easily used while wearing gloves. Ten user programmable configurations are available for use with repetitive jobs.

Unique quick connect system is easy to use; simply press down on the top of the terminal and insert bare wires (up to 3 millimeters or 10 AWG) or compensated thermocouple connectors.  When releasing the terminal, wires are held tightly between two brass plates for thermal stability, creating excellent cold junction compensation for thermocouples.  This systems also allows for the use of 4 millimeter banana plugs or safety plugs to be connected to the front panel.

The C75 allows the following physical values to be measured and simulated:

  • Voltage
  • Current
  • Resistance
  • Temperature, via resistive probes and thermocouples
  • Pressure measurement when used with optional external pressure module.  Pressure simulation requires user supplied pressure pump.

These functions allow scaling of process signals and corrections to temperature probes. The C75 is compatible with HART transmitters by inserting a 250 ohms resistance, allowing uninterrupted data transfer. Data can be stored and sent to PC for analysis.

The dual display simultaneously shows measurement value, emitted value, gauges, and used functions.

Selectable resolution allows the user to adjust in order to meet specific testing requirements. The top line displays date, time, and external temperature.  While measuring average, maximum, minimum, and the number of measurements are shown on the left of the screen. During emission the left of the screen will display ramps, steps, and constant value emission functions.  Access drop-down menus using the navigator.

View the spec sheet for complete information on this item.




File Menu: Save up to 10 full configurations of the instrument, and recall them as desired.
Contrast Adjustment


Rechargeable NiMH Batteries.


Screen backlighting is adjustable to save battery life

Battery Life

5 to 10 hours depending on functions used


Allows process signals to be displayed in a percentage of full scale (or in all other units), during measurement and simulation. Allows sensors to be corrected after a calibration.

Relative Measurement

Programming of a reference value different from the one of the instrument (NULL function).
Subtracting of constant value by measuring or by programming from a measured value (TARE functions).

Square Root

Takes into account a quadratic signal coming from a ΔP transmitter.

Statistical Functions

Average, Minimum, Maximum, and number of measurements done are always displayed. Reset key allows values to be updated.

Transmitter Tests

Transmitters can be verified using user procedures. Twenty procedures can be stored, as well as test results. Deviation curves are displayed.

Simulation Menu

Simulation value is set by entering value on keypad or using the cursor to change the appropriate digit.

Ramps Generation

Starting, ending, and length of time values of simple or cyclic ramps can be simulated. The number of ramps can be adjusted in case of cyclic ramps for any signals.

Steps Simulation

2 modes provided: Program mode and manual mode.
In program mode, select the starting value, number of steps, and the duration of the step.
In manual mode, the user has approximately one hundred preset values.
In current simulation the user will have additional preset values in function of range and according to 0%, 25%, 50%, 75%, and 100% from the selected gauge.
Choice is made between gauges: 0-20mA, linear or quadratic OR 4-20mA, linear or quadratic.


100 programmable values allows complex curves to be generated.

Transmitter Function

C75 is able to be used as a transmitter. Measurement input is copied on the output with scaling.

Pressure (Optional)

Add optional absolute or relative pressure modules (sold separately) to add pressure measurement capability.  Pressure simulation requires user supplied pressure pump.


Five user selectable languages: English, French, Spanish, German, and Italisn.

Display Resolution

User selectable to allow measurements to meet specific testing requirements.

Maximum Ambient Conditions

-10° to 55°C, 10 to 80% Relative Humidity


1.9 pounds (900 grams)


8.3 inches x 4.3inches x 2.0 in. ( 210mm x 110mm x 50mm)

Included Accessories

Protective boot, 6 testing leads with alligator clips, quick charging battery system, neck/shoulder strap, stand for desktop use, and user manual.

Switch Test

For temperature or pressure, the C75 can control the trigger levels for electronic thermostats and pressure switches.


Record data automatically or on user request. 10,000 data can be stored and displayed on the screen as a curve or list.

IP Rating

IP 54

NIST Traceable Calibration Available?



One Year