Increasing Measurement Flexibility with the HH-A-2.5 Automatic CMM Probe Head Range

by Glen Wiltshire on May 1, 2019 From Technology, Ask The Experts

A coordinate measuring machine (CMM) is made up of numerous components that can all contribute to driving a manufacturer’s productivity. It isn’t just about making the CMM operate efficiently – it’s about finding the best component to meet the user’s needs and objectives.

The probe head is at the centre of the CMM, working with the sensor to generate that crucial measurement data. Smooth inspection and efficient data capture relies on users selecting the right combination of probe head and sensor.

The key is to identify what you really want to get out of the machine. In this blog, we’ll explore the probe head that we designed for operators wanting to get more measuring flexibility while reducing cycle times.

Increased Measurement Flexibility and Faster Inspection

Parts with difficult to access features are easier to tackle with probe heads offering a high number of indexable positions. The HH-A-2.5 automatic probe head range is purpose-built for complex parts.

The HH-A-T2.5 probe head is capable of 12 240 unique positions and indexing in 2.5 degree increments. Due to increased rotation of the A Axis, the HH-A-H2.5 model can achieve 20 736 unique positions.

Feature access is further enhanced with the range’s very high rotational torque. The HH-A-T2.5 enables a maximum extension length of 450 mm, while the HH-A-H2.5 offers 750 mm.

For manufacturers whose parts are becoming increasingly complex, being able to use both tactile and non-contact probing can be key. That’s why we ensured the HH-A-2.5 probe heads are compatible with all Hexagon TKJ and M8 sensors, for everything from single point probing to complex optical measurements:

  • Touch-trigger probes – fast and repeatable 3D measurements
  • Scanning probes – quick and accurate counter and shape inspection
  • Laser scanners – precise and rapid collection of high-density point cloud data
  • Optical sensors – highly accurate and reliable non-contact measuring

For users who need tactile and non-contact sensors at the ready, the probe heads are fitted with a kinematic joint (TKJ) which can be connected to a multiwire to transform your CMM into a multisensor system.

Stylus and sensor changes are made more efficient with the option to automate probe swapping during measurement routines. The HH-A-T2.5 and HH-A-H2.5 are compatible with the HR-R Probe Changer Rack, enabling automated sensor changes without the need for requalification.

Manufacturers looking to increase throughput are catered for with the probe head’s high rotation speed of 90 degrees in 2.5 seconds. 


We know that process requirements can quickly change; the HH-A-2.5’s modularity is designed to help you react fast and meet new demands.

Upgrading to the HH-A-T2.5 or HH-A-H2.5 comes as a complete package, with a cable set, head controller, installation, and all required accessories for optimal interfacing with your CMM.

The HH-A-2.5 model can be mounted on the CMM with a shank or flange, while the HH-AS-2.5 model can be mounted on any CMM with an 80 mm ram.

To learn more visit the HH-A-T2.5 product page and the HH-A-H2.5 product page.

Glen Wiltshire

Glen Wiltshire is responsible for the strategic product management activities for CMM probe and sensor products at Hexagon Manufacturing Intelligence. He joined the company in 1996 and has a wealth of experience in service and operation within a commercial operations environment.

HH-A-H2.5 / HH-AS-H2.5 Автоматические измерительные головки

У HH-A-H2.5  возможность индексирования в 20 736 уникальных положениях с шагом 2,5 ° благодаря увеличенной способности вращения оси A (± 180°).

HH-A-T2.5 / HH-AS-T2.5 Автоматические измерительные головки 2,5°

У HH-A-T2.5 возможность индексирования в 12 240 уникальных положениях  с шагом  2,5°.