In modern manufacturing, moving a heavy workpiece to a metrology room takes time, manpower, and money that production schedules rarely allow. The real demand is for accurate contact measurement on-site — around complex geometries, inside narrow cavities, deep into holes, and across cleanroom environments where contamination control is non-negotiable.
The PMT portable measuring arm was built around this challenge. With 6 to 7 degrees of freedom, a lightweight carbon fiber build, and a wide range of mounting and probe configurations, it gives operators the physical flexibility to reach measurement points that fixed-station CMMs cannot — without sacrificing accuracy.
Flexible Positioning: The Measurement Equipment That Comes to the Workpiece
For large, heavy, or structurally complex workpieces, transporting the part to a measurement instrument is often impractical. The PMT portable measuring arm reverses this relationship — the instrument comes to the workpiece instead.
The arm is constructed from aerospace-grade carbon fiber, keeping total weight between 8.8 and 12 kg. A recessed carry handle allows a single operator to transport and position the unit with one hand. Whether setting up beside a workpiece on the shop floor or mounting directly onto the part fixture, the arm is ready to measure within minutes.
Tripod Mounting — Stable Setup Alongside the Workpiece
PMT’s foldable height-adjustable tripod extends from 730 mm to 1,200 mm, providing a stable measurement base across a wide range of floor-level and elevated applications. Made from aerospace aluminum, it is both lightweight and capable of supporting up to 8 kg of load. Five-level damping adjustment prevents sudden drops during height changes, protecting the arm and maintaining setup stability throughout the measurement session.
Magnetic Base Mounting — Fixed Directly to Steel Structures
For setups on carbon steel platforms, welding fixtures, or other steel structures, PMT’s high-strength integrated magnetic base provides a secure, 360°-adjustable mounting point. The arm stays firmly in position throughout contact measurement, reducing the risk of positional drift and keeping results consistent across the session.
Vacuum Base Mounting — For Non-Magnetic Surfaces
On glass, granite, marble, or other non-magnetic surfaces, PMT’s electric vacuum base achieves a secure hold in 0.5 seconds. A real-time battery indicator prevents unexpected shutdowns mid-measurement, allowing the operator to focus entirely on the inspection task without monitoring the equipment’s power status.
Together, these mounting options make the PMT portable measuring arm a genuinely versatile on-site measurement platform — quick to deploy, stable in operation, and adaptable to the surface conditions found across virtually any production environment.
Flexible Probing: Contact Measurement With No Dead Angles
Portable positioning solves the problem of getting the equipment to the right location. The probing system has to do the rest. PMT’s contact measurement capability is designed to handle the geometries and access constraints that traditionally cause measurement failures on the shop floor.
Cavity Measurement
Internal cavities are one of the most persistent pain points in on-site inspection. Conventional probe setups are restricted by reach and angle — making it difficult to contact internal surfaces correctly, or at all, without partial disassembly.
With 6 to 7 degrees of freedom and 360° continuous joint rotation, the PMT portable measuring arm allows the probe handle to be maneuvered through openings and around obstructions, reaching into cavities without disassembly. The operator can freely adjust the approach angle until the probe contacts the target surface at the correct orientation — capturing valid dimensional data from locations that would otherwise require the workpiece to be taken apart.
Narrow Space Measurement
The same range of motion applies where surface obstructions block direct access to the measurement zone. The arm navigates around these obstacles while PMT’s standard 3 mm zirconia probe — compact enough to enter narrow gaps — makes contact with the target surface directly.
This combination enables reliable capture of flatness, parallelism, and other geometric tolerances at confined assembly interfaces. For different applications, PMT offers zirconia probes ranging from 2 mm to 8 mm in diameter, allowing the probe configuration to match the actual measurement geometry rather than working around it.
Deep Hole Measurement
Deep holes in large machined components, structural parts, and equipment bases present a specific probing challenge: standard probes cannot reach the bottom of the hole, and long stylus extensions introduce deflection errors that reduce accuracy.
PMT’s arm supports extension bar attachments to increase probing depth without deflection, enabling accurate diameter and positional data from holes that would otherwise require specialized gauging equipment. For micro-holes requiring finer access, pointed needle extensions are available as an additional configuration option — giving the system a complete answer to hole inspection across a wide range of sizes and depths.
Cleanroom Measurement
In cleanroom environments — medical devices, precision optics, and semiconductor-adjacent manufacturing — the priority is minimising disruption and contamination to the production environment. Moving parts out of a cleanroom for inspection, then returning them for reassembly, introduces contamination risk and adds time to the production cycle.
Using the PMT arm directly on the shop floor during assembly allows operators to measure and adjust components in real time, with deviation values visible in the software as the inspection proceeds. Adjustments can be verified immediately against defined tolerance ranges, eliminating the need for a second round of handling. The result is faster assembly validation, a cleaner production cycle, and fewer opportunities for contamination between inspection and final assembly.
What Users Say
“Large workpieces used to mean forklift trips to the metrology room — easily half an hour each way. With the PMT arm, we set up the tripod on the production line and measure right there. Our yield rate went from 60% to over 95%, and within six months the savings on transport and rework had paid for the equipment.” — Factory owner, manufacturing sector
“Internal cavities on rotary machines, valve body holes — these used to take forever with a bore gauge, and one unsteady hand and the reading was worthless. With the PMT arm, the probe goes straight in, we set the coordinate system, take a few points, and diameter, roundness, and coaxiality all come out together. The arm is light enough that it’s not tiring to use even on a long shift.” — Process engineer, manufacturing sector
Conclusion
The PMT portable measuring arm combines portable deployment, multi-surface mounting options, and high-degree-of-freedom contact probing into a single on-site measurement solution. Whether the application involves enclosed cavities, narrow assembly gaps, deep hole inspection, or controlled production environments, the arm adapts to the measurement geometry rather than requiring the workpiece to adapt to the instrument.
For manufacturers looking to reduce handling time, improve yield rates, and bring dimensional control directly to the production line — without sacrificing measurement accuracy — the PMT portable measuring arm offers a proven and practical solution.
Ready to find the right configuration for your production environment? Contact the PMT team to discuss your measurement requirements.
