M3 Digital Display

The Metro M3 Inductive is the last-generation tool for dimensional control with 1 or 2 Inductive probes. Despite being older tech, the Metro M3 provides users with accurate readings on an easy-to-read display, making the measurement of unusually-shaped objects more straightforward than ever.

One of the hardest parts of measuring objects is knowing exactly what the results are. Our digital display air gages provide you with all the details you need on a screen that’s easy to navigate and provides many options to tailor your experience as needed. If this sounds like the upgrade you need for your equipment, look no further than our Metro M3 Inductive. We know you’ll be more than satisfied with this purchase, but if you want to learn more about these devices, we have further product information about them below.

Several versions are available, allowing you to connect inductive probes from any brand:

  • Metro
  • Tesa
  • Mahr

Product advantages 

  • Touch screen
  • Very easy to use
  • Economic
  • USB communication as a keyboard to a computer
  • Static and dynamic measurement
  • Designed for industry condition
  • Combined measurement (with 2 probes) , sums, differences ...


  • 4.3” Resistive touch screen display (glove-friendly use)
  • Digital readout with multiple communication capabilities (USB, remote control the device or send the measurement to an external system).
  • 2 measurement configurations (2 characteristics)
  • Different display modes with 1 or 2 measurements, with or without tolerances.
  • Tolerance limits and control limits (Warnings).
  • Absolute or relative measurement
  • Direct or dynamic measurement (Min, Max, Max-Min , Average, Median)
  • USB communication "virtual keyboard"
  • Modbus-RTU or ASCII Communication on RS232
  • Sorting by classes of size, up to 16 classes by characteristic
  • Possibility to connect an optional I/O module with 8 optocoupled I/O.
  • Possibility to connect a multi-function foot switch (measurement transfer, calibration etc...)
  • Optional external module for temperature compensation from PT100 sensor or Type K thermocouple.
  • Easy to use and reliable


Many functions and measurement mode can be selected through the touch screen:

  • Tolerance limits, Control limits (warnings) Dimension of the master piece (reference piece) .
  • Calculation formula (C1, C2, -C1, -C2, C1+C2, C1-C2, -C1+C2, -C1-C2, 3 points diameter)
  • Calibration
  • Different display modes with 1 or 2 characteristics displayed
  • Direct or dynamic measurements (Max, Min, Max-Min, Average, Median)
  • Absolute or relative measurements
  • Sorting by classes of size, up to 16 classes by characteristic
  • Measurement direction inversion
  • Possibility to lock selected functions with a password
  • Display resolution (from 2 to 5 decimals)
  • M-Bus connector for the optionnal connection of a module with 8 input/outputs (go, nogo, preset, send measurement etc...)
  • Metric (µm or mm) or imperial measurements (inches)
  • Selection between 2 measurement configurations (2 characteristics)
  • Automatic change of program by moving the probes
  • Different languages already installed. New languages can be installed upon request

Part Numbers:

13010:  M3 with 2 inputs for inductive probes (Metro)

1301T:  M3 with 2 inputs for inductive probes (Tesa)

1301M:  M3 with 2 inputs for inductive probes (Mahr)

18193: Cable with Digimatic output for Mux and Mitutoyo DP1 printer

45160: RS232 communication cable to PC

18020: Multifunction footswitch



MB-IO:  This M-Bus module is fitted with 8 input/outputs isolated with optocouplers allowing to get additional functionalities, for example, output for Go/noGo, input for preset or start dynamic measurement... The M-Bus modules are mounted on an aluminum profile allowing to mount them on a standard DIN rail. More information on this page: M-BUS 

As an option, it is possible to connect up to 4 M-Bus I/O module fitted with 8 optocoupled inputs/outputs. (= max 32 I/O).  A screen allows the user to assign a function to a pin of the module very easily. 8 virtual Buttons/lamps allow for easy testing of your wires.

Available functions:

  • Go/NoGo
  • Calibration/Preset
  • Start dynamic measurement
  • Measurement transfer
  • Zero
  • Stop

Multifunctional Footswitch (P/N 18020):  The footswitch can be configured in different ways: preset, measurement transmissions, start dynamic measurements, and more.

M-Bus Cable for M3 (P/N 81213-1.5):  This cable allows to connect the compatible M-Bus modules (MB-IO, MB-RL and MB-TP) on an M3 display unit (MB-IO, MB-RL and MB-TP)

Magnescale probe adapter for M2/M3 TTL (P/N 24062):  This cable allows for the connection of 1 Magnescale probe on a M2 (P/N 15000) or M3 (P/N 13000) display.  It can integrate an electronic board that manages the error signal form from the Magnescale probes.

Heidenhain M23 to D-SUB 15 adapter for M2/M3 (P/N 84100):  This cable allows for the connection of 1 Heidehain prob like the MT12 or the MT25 with the round M23 connector on the M2 or M3 display.

Mitutoyo LG Adapter for the M2/M3 TTL (P/N 24061):  The cable allows for the connection of 1 Mitutoyo probe on a M2/M3 display.

RS232 Communication Cable (P/N 45160): This cable allows for connection from a M2/M3 display to a computer.

RS232 to Digimatic communication cable (P/N 18193):  This cable allows for the M1/M3 display connection to a multiplexer Mux from Metro.

RS232 to USB communication cable (P/N 45173):  This cable allows for the M1/M3 display t to communicate with a computer.  This creates a virtual COM port on the computer and is its delivered with a drive in CD format.


USB Connection

The M3  is fitted with a mini-USB connector with 2 functions : 

  1. Power supply through a wall-mounted transformer. This transformer supplies a regulated 5V/1A DC voltage. 
  2. Measurement transmission. If you connect your M1/M3 to a PC, the PC will detect and install automatically the M3 as a standard USB keyboard with the standard drivers of your operating system (Windows, Mac OS, etc.). When you will send the measurement, the value will be written on your PC screen where your cursor is, in the same way as it would have been typed with a keyboard. 

No need to install any specific driver or software.



The RS232 interface allows us to monitor and configure all the M3 functions through ASCII commands or MODBUS-RTU protocol. 


Below are examples of the graphic interface used on the M1 or M3 units.





Retrofit of a gauging fixture that was mounted with needle indicators on a 100% sorting working place:
Out-of-round (Max-Min) measurement on 2 points of a cylindrical part. Measurement starts with a footswitch.
Customer benefit: Accuracy increased (1/10th of Micron), instantaneous reading of the 2 characteristics without the risk of wrong reading of the needles. Measurement transmission to a central SPC/ERP software.



Communication between a M3 display and a Proface PLC with the Modbus RTU protocol. The HMI from Proface has been programmed with differents buttons and indicators allowing for the control and transfer of information from the M3.


Measurement of a diameter in 3 points

Call us today: (815) 242-0027

We will come up with a solution that fits your needs.