Proceq Equotip Piccolo
Portable Hardness Tester
Test Method

The EQUOTIP measuring principle

The EQUOTIP measuring principle is physically a rather simple, dynamic hardness test. An impact body with a hard metal test tip is propelled by spring force against the surface of the test piece. Surface deformation takes place when the impact body hits the test surface, which will result in loss of kinetic energy. This energy loss is calculated by velocity measurements when the impact body is at a precise distance from the surface for both the impact and rebound phase of the test. The permanent magnet in the impact body generates an induction voltage in the single coil of the impact device. The voltage of the signal is proportional to the velocity of the impact body, and signal processing by the electronics provides the hardness reading for display and storage.

The EQUOTIP hardness scale “HL”

The hardness value HL was first introduced into measuring technology in 1975, when the method and the instrumentwere presented by its inventors Leeb and Brandestini (Swiss Patent 596550). The ratio between rebound velocity vrand impact veolocity vi multiplied by 1000 is taken to calculate the hardness value HL (HL = hardness in LEEB units). Method and instrument are named EQUOTIP derived from Energy QUOtient recalling the principle of energy measurement.The PICCOLO is the latest tester in the tradition of the EQUOTIP System.

Hence, HL is a direct, standardized (ASTM A956) measurement of hardness. In contrast to static hardness testing,dynamic hardness test results contain additional information on reactive behavior of materials, e.g. on elasticproperties of the material. Correlations to other hardness scales like Rockwell C (HRC) or Brinell (HB) are available and programmed as a standard feature in the PICCOLO. Converted values can be directly displayed on the large LCD. As conversions between different hardness scales are always material dependent and affected by some loss inaccuracy, an extensive set of material specific conversions are available. With the PICCOLO the user can easilyprogram his “company's own” conversions for those alloys and materials not included in the standard list by using industry accepted empirical tests.

Testing with EQUOTIP PICCOLO-Easy as 1-2-3

1. Place the PICCOLO on the surface point to be tested, perpendicular to the surface.
   Recommendation: grasp the PICCOLO between the housing and the support ring and press firmly against the surface.

2. Loading the impact device – slide the actuator towards the housing. The catch chuck grasps the impact body and draws it against the energy spring to a defined force. This motion “wakes up” the electronics and the display shows the current test settings.

3. Measuring is accomplished by again sliding the actuator towards the housing. This releases the impact body from the catch chuck and propels it towards the test surface within the defined energy. Results are immediately displayed in the selected scale. No separate trigger action is necessary – loading and release is accomplished in the same motion.
   Recommendation: space the impacts 3 mm to 5 mm apart, and average 3 to 5 single values for each data point.

Suitable test specimens are primarily large, massive parts. Owing to the dynamic mode of action, it should be ensured that the specimen does not move or oscillate during the measurement. Parts which are too thin or thinly coated need special effort to assure reliable results. The measured surface must be clean and dry. Surface roughness should be betterthan ISO N7. Excessive scattering of test result indicates poor surface preparation.

Configuring the EQUOTIP PICCOLO

EQUOTIP PICCOLO full bi-directional communication