TEX with return spring Novotechnik | Linear probe

Automatic return allows you to use TEX as displacement probe This method is used when it is necessary to measure a position by contact without mechanically fixing the probe to the workpiece. The sensor follows the movement of the surface while the spring keeps the probe tip in contact.

Dimensional control and parts tracking

• Measurement of displacements by direct contact.
• Tracking of profiles, surfaces, and moving components.
• Checking initial, final and intermediate positions.
• Dimensional verification and race control.
• Repetitive measurements on tooling and control devices.

Machinery and automation

• Position control of moving components.
• Displacement feedback in machines and automatic systems.
• Measurement without permanent mechanical connection between the sensor and the part.
• Linear motion tracking with automatic probe return.

Test benches and laboratory

• Displacement recording during mechanical tests.
• Verification and dimensional measurement equipment.
• Repetitive motion tests.
• Displacement measurement along with force, pressure, torque, or other variables.

The threaded tip M2,5 It also facilitates the use of compatible probe tips when the geometry of the application requires a different form of contact.

The element whose position is to be measured acts directly on the probe tip. As the part moves, the stem enters the sensor body and internally moves the potentiometric cursor.

When the piece moves in the opposite direction or stops pressing the tip, the return dock The stem is then moved back to its extended position. This eliminates the need to rigidly connect the sensor to the component being measured.

The specified horizontal drive force is 5.6 ±0.8 N at 20 °C. This force must be taken into account when measuring lightweight, flexible, or pressure-sensitive components.

Uncontrolled release of the spring against the internal stops should be avoided, and the stem should not be lubricated.

The stem is made of stainless steel 1.4305 / AISI 303. At its end, a stainless steel probing tip is installed with M2.5 external thread and a pressed hard metal ball.

The M2.5 thread allows the contact element to be adapted to the mechanical needs of the application using compatible probe tips.

To maintain the specified repeatability and avoid irregular wear, the movement must be performed aligned with the longitudinal axis of the sensor and without transmitting significant lateral loads to the stem.

The dynamics of the return system depend on the selected path. The maximum frequency specified in the center position is:

• 10 mm: 49 Hz.
• 25 mm: 43 Hz.
• 50 mm: 35 Hz.
• 75 mm: 28 Hz.
• 100 mm: 24 Hz.
• 125 mm: 21 Hz.
• 150 mm: 20 Hz.
• 175 mm: 20 Hz.
• 200 mm: 20 Hz.

These values correspond to the maximum frequency indicated for the center position. Actual performance also depends on the stroke used and the mechanical conditions of the application.

The TEX with return spring is a linear potentiometric transducer. The movement of the probe displaces a multi-wire cursor of precious metal on a resistive track of conductive plastic.

The sensor should be used as voltage divider with virtually no load on the cursor. The signal obtained is ratiometric and proportional to the mechanical position of the probe.

Depending on the selected path, the nominal resistance is between 1 and 8 kΩ. The recommended current across the cursor is less than 1 µA and the maximum permissible voltage is 42 VDC.

It does not directly incorporate a standard industrial output of 0–10 V or 4–20 mA. When the PLC, indicator, or acquisition system requires one of these signals, a compatible signal conditioner can be used.

Since it is an absolute measurement, the probe position is obtained directly from the potentiometric signal and it is not necessary to perform a reference search after a disconnection.

The family is available with two mechanical versions:

• 421 · Return spring + clamps: Available for travel distances from 10 to 200 mm. Two clamps and four M5x20 screws are supplied.
• 428 · Return spring + M10 center mount: Available for travels from 10 to 150 mm. The maximum tightening torque on the collar is 5 Nm.

Clamp mounting allows the sensor body to be attached directly to a structure or support. The version with an M10 center thread allows it to be passed through a mounting plate or bracket and the probe's position relative to the workpiece to be adjusted.

The type of electrical connection is defined by the last three digits of the reference:

• 101: M8x1 3-pole radial connector.
• 202: 2m shielded PUR cable, radial output.
• 205: 5m shielded PUR cable, radial output.
• 302: 2m shielded PUR cable, axial output.
• 305: 5m shielded PUR cable, axial output.

Electrical allocation

• End of track 1: pin 1 / BN · brown.
• Cursor signal: pin 4 / WH · white.
• End of track 3: pin 3 / GN · green.

In versions with an integrated cable, the display must be grounded. Pin 4 corresponds to the cursor signal, and pins 1 and 3 correspond to the ends of the resistive trace.

The reference is constructed following the format:

TEX-RRRR-MMM-002-CCC

• RRRR: route: 0010 / 0025 / 0050 / 0075 / 0100 / 0125 / 0150 / 0175 / 0200.
• MMM = 421: return spring and mounting using clamps.
• MMM = 428: return spring and M10 center mount, available up to 150 mm.
• 002: linearized resistive element, standard version.
• CCC: connection code 101 / 202 / 205 / 302 / 305.

Example: TEX-0100-421-002-101 corresponds to a 100 mm TEX with return spring, clamp mounting and M8x1 radial connector.

Example: TEX-0150-428-002-202 corresponds to a 150 mm TEX with return spring, M10 central fixing and 2 m shielded radial PUR cable.