Les Côtes 2, CH-2525 Le Landeron, Switzerland
Les Côtes 2, CH-2525 Le Landeron, Switzerland
Half-bridge inductive probes with ≤ 0.02 μm repeatability. TESA compatible, switchable bridge configuration, and built to perform under the harshest production conditions.
PRETEC electronic measuring probes are half-bridge inductive displacement sensors designed for high-precision dimensional inspection. They work by detecting the change in position of a ferromagnetic core within a coil system. When the measuring bolt contacts the workpiece, the core moves, altering the inductance of the coil, and this change is converted into an extremely precise displacement reading.
Unlike LVDT (Linear Variable Differential Transformer) probes that use three coils, the PRETEC half-bridge design uses two active coils arranged differentially. When the core moves in one direction, one coil's inductance increases while the other decreases. This differential arrangement provides inherent temperature compensation and doubles the sensitivity compared to a single-coil design.
The coils form two arms of a Wheatstone bridge circuit, with the other two arms completed inside the display unit. PRETEC probes are uniquely switchable, the bridge configuration can be changed at the customer site by switching inside the connector, providing direct compatibility with TESA and other manufacturers' readout systems without replacing the probe itself.
All PRETEC probes share a standard Ø 8 mm body diameter and are mechanically interchangeable with probes from TESA, Mahr, Marposs, and other manufacturers using the same form factor. One probe, multiple display systems.
Repeatability ≤ 0.02 μm across all models. Linearity ± 0.3% of measuring range.
Switchable bridge inside connector. Works with TESA, Mahr, and other display systems.
Hardened Ø 8 mm body withstands continuous production use without dimensional drift.
Measuring bolt on precision ball bearing. Roller bearing prevents rotation and distortion.
Pre-travel and post-travel continuously adjustable from the back of the probe.
Spring push, pneumatic push, or vacuum retract, matched to your application.
Both cable exit configurations available. Radial kit included with universal model 2940.
Custom springs, cable length up to 20m, logo engraving, special contact points available.
Six standard models cover the full range of production measurement needs, from universal spring-push to specialized pneumatic and low-force parallelogram designs.
The most versatile PRETEC probe. Best universal model with a total range of 4 mm. Configurable to axial or radial cable connection, radial kit included in every package.
Vacuum-retracted probe for automated gauging applications where the measuring bolt must retract during part loading/unloading. Axial cable connection.
Same vacuum retraction as the 2922 but with radial cable and pneumatic input connections. Ideal for tight fixture configurations.
Enhanced protection rating for wet environments. Spring-actuated with IP 65 splash-waterproof body, suitable for measurements near coolant exposure.
Pneumatically actuated probe for automated systems. Adjustable measuring force via air pressure (0.6–1.1 bar). Total range of 4 mm, axial cable connection.
Parallelogram spring mechanism for ultra-low measuring force (0–0.25 N). Designed for thin-walled, delicate, or easily deformable workpieces. Adjustable force knob.
All PRETEC probes share the same electrical characteristics, ensuring full interchangeability across the product range.
| Model | Travel (± mm) | Pretravel | Total Travel | Repeat. [μm] | Linearity | Actuation | IP | Cable |
|---|---|---|---|---|---|---|---|---|
| 2940 | ± 2 mm | 2.1–2.3 mm (var.) | 4.2 mm | < 0.02 μm | ± 0.3% | Spring | 64 | Axial + Radial |
| 2922 | ± 1 mm | 1.5–1.7 mm (fix) | 3.2 mm | < 0.02 μm | ± 0.3% | Vacuum | 64 | Axial |
| 2923 | ± 1 mm | 1.5–1.7 mm (fix) | 3.2 mm | < 0.02 μm | ± 0.3% | Vacuum | 64 | Radial |
| 2924 | ± 1 mm | 1.5–1.7 mm (fix) | 3.2 mm | < 0.02 μm | ± 0.3% | Spring | 65 | Axial |
| 2980 | ± 2 mm | 2.1–2.3 mm (fix) | 4.2 mm | < 0.02 μm | ± 0.3% | Pneumatic | 64 | Axial |
| 2981 | ± 2 mm | 2.1–2.3 mm (fix) | 4.2 mm | < 0.02 μm | ± 0.3% | Pneumatic | 64 | Radial |
| 2952 | ± 1 mm | 1.05–1.1 mm (fix) | 2 mm | 0.01–0.05 μm | ± 0.3% | Parallelogram | 64 | Axial |
Standard supply: All probes include 2 m PUR cable, NBR rubber gaiter (dust shield), and DIN connector. Custom options: Cable length up to 20 m, cable insulation types (PUR, PVC, PE, PP, Silicone), gaiter materials (NBR, SBR, Viton), custom engraving with your logo and serial numbers.
All PRETEC probe models, dimensional drawings, and accessories, page by page. Navigate with the arrows or click any thumbnail below.
PRETEC probes are designed to maintain sub-micron repeatability even in aggressive production environments, surrounded by coolant mist, metal chips, vibration, and continuous thermal cycling.
A comprehensive range of standard and custom accessories allows you to adapt PRETEC probes to any measurement configuration. All items available from stock or manufactured to your specification.
PRETEC probes are application-matched. Here is what we need to recommend the correct model and configuration.
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Technical answers about PRETEC half-bridge inductive probes, compatibility, specifications, and applications.
Need help choosing the right probe model? Our engineers are ready to assist.
Ask a Technical QuestionAn LVDT (Linear Variable Differential Transformer) uses three coils: one primary and two secondaries. The core's position determines the ratio of voltage induced in each secondary. A half-bridge uses two active coils arranged as two arms of a Wheatstone bridge, with the other two arms inside the display unit. The half-bridge design is simpler, provides inherent temperature compensation, and is the standard used by TESA, making PRETEC probes directly compatible with TESA readout systems.
Yes. All PRETEC probes are designed with TESA compatibility as a core feature. They operate at the same carrier frequency (13 kHz), use the same sensitivity standard (73.75 mV/V/mm), and feature a switchable bridge inside the DIN connector that can be set to match the TESA pin configuration. You can swap a TESA probe for a PRETEC probe on your existing TESATRONIC display without any reconfiguration of the readout electronics — just set the bridge switch and recalibrate.
Different probe manufacturers wire the half-bridge coils to different pins in the DIN connector. This means a probe designed for one brand's display won't work correctly on another brand's display, even though the connector fits physically. PRETEC solves this with a small switch inside the connector body that reconfigures the pin assignment. By changing the switch position, the same PRETEC probe can work with TESA, or with PRETEC's own display units, or with other compatible systems — without changing any hardware.
For automated systems, choose based on how the workpiece is loaded. If the probe must retract during part loading, use the 2922/2923 (vacuum retract). If you need controlled and adjustable measuring force, use the 2980/2981 (pneumatic push) — the force varies with air pressure (0.6 to 1.1 bar). For integration into parallel guiding fixtures, any Ø 8 mm PRETEC probe fits directly.
For spring-actuated probes (2940, 2924), the measuring force at electrical zero is typically 0.45 to 0.75 N. For pneumatic probes (2980/2981), the force depends on the applied air pressure: 0.5–0.7 N at 0.6 bar or 0.85–1.15 N at 1.1 bar. For ultra-delicate parts, the low-force parallelogram model 2952 provides 0 to 0.25 N with a manual adjustment knob. The total contact force is composed of spring force + rubber gaiter resistance + shaft weight + tip weight.
Standard supply is 2 meters of PUR cable. Extension cables are available in 1 m, 5 m, and 10 m lengths, and any custom length up to 20 meters is possible. Cable insulation options include PUR (standard), PVC, PE, PP, and Silicone — selected based on your environmental requirements (temperature, chemical exposure, flexibility).
Standard probes carry an IP 64 rating, protecting against dust and water splashes. For applications with direct coolant exposure, choose the model 2924 with IP 65 splash-waterproof protection. The rubber gaiter (dust shield) material can also be upgraded from standard NBR to Viton for improved chemical resistance against aggressive coolants and cutting fluids.
The 2952 uses a parallelogram spring mechanism instead of a conventional coil spring. This provides extremely low and precisely adjustable measuring force (0 to 0.25 N via a knob), making it suitable for thin-walled, elastic, or easily deformable workpieces where even 0.5 N of contact force would cause measurable deflection. Note that the 2952 does not use ball-bearing guidance — the parallelogram itself provides the linear motion.
Yes. PRETEC offers OEM customization including laser engraving with your company logo, custom product names, and serial numbering. Beyond cosmetic customization, we can also modify the measuring force (custom springs), cable insulation type and length, and gaiter material. Contact us with your specifications for a quotation.
With proper use and maintenance, PRETEC probes deliver reliable performance for millions of measuring cycles. The primary wear components are the ball bearings and the spring — both designed for extended service. The carbide-chromed body shows negligible dimensional change. Periodic repeatability checks using calibrated gauge blocks will indicate when a probe is approaching the end of its service life.
PRETEC probes are competitively positioned against established brands while offering the unique advantage of switchable bridge compatibility. Because they are manufactured in-house by PFL Group in Switzerland using the same quality standards and materials as premium competitors, you receive equivalent or superior performance with more flexibility and customization options. Contact us for a detailed quotation based on your volume and specifications.
All PRETEC probes are designed and manufactured in Switzerland by PFL Antralux SA in Le Landeron. The complete production chain — from coil winding and body machining to final assembly, calibration, and testing — is performed in-house. This vertical integration ensures consistent quality control and allows rapid customization. The PFL Group also has sales and engineering offices in France, Romania, Serbia, and Slovakia.
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