Sauter HMM-NP portable Leeb hardness tester, 170 to 960 HLD, sensor D, with hardness reference block
€954.00
% Manufacturer's RRP: €1,060.00 10% below manufacturer's RRP
- Portable Leeb hardness tester, measuring range 170 to 960 HLD, readability 1 HL
- External rebound sensor type D and hardness reference block (790 ± 40 HL) in the scope of delivery
- Conversion to HV, HB, HRB, HRC and MPa, tensile strength for steel 375 to 2,639 MPa
- Measurement in all directions (360°), measurement accuracy ± 1 % at 800 HLD
- Memory for 9 measured values, mini statistics, model without printer
- Plastic housing, approx. 0.25 kg, battery-operated with 3 x AAA, carrying case
ⓘ This product description has been translated from German using AI. Despite careful review, we do not guarantee that the translation is error-free; in case of doubt, the German version shall prevail.
Product information "Sauter HMM-NP portable Leeb hardness tester, 170 to 960 HLD, sensor D, with hardness reference block"
The Sauter HMM-NP measures the hardness of metals using the Leeb method in a compact plastic unit with an external rebound sensor type D. It covers 170 to 960 HLD and reads to 1 HL. The device automatically converts measured values to HV, HB, HRB, HRC and tensile strength in MPa. A hardness reference block (790 ± 40 HL) and a carrying case are included in the scope of delivery. According to Kern, the designation ‘NP’ refers to the version without a printer; the other features correspond to the HMM model.
How the Leeb measurement works
In the rebound sensor, a test body is propelled by a spring against the test object. Depending on its hardness, the object absorbs some of the kinetic energy. The device measures the reduction in velocity and converts it into a Leeb hardness value. An automatic compensation function compensates for the test direction, which is why measurements can be taken in all directions (360°). According to Kern, the measurement accuracy is ± 1 % at 800 HLD (± 6 HLD).
Requirements for the test object
According to Kern, the test object must be at least 3 mm thick; with firm coupling on a solid base, a weight of 2 kg is sufficient. The minimum radius of curvature (concave or convex) is 50 mm; with a stabilising ring, it is 10 mm. The device specifies the tensile strength for steel in the range from 375 to 2,639 MPa. The hardness reference block serves as a standard for adjusting the instrument.
Memory and display
The internal memory stores up to 9 measured values. The mini statistics display shows the measured value, average value, measurement direction, date and time. The LCD displays the values in the selected unit. The device runs on three AAA batteries (1.5 V), which are included in the scope of delivery, and switches itself off after 3 min.
Typical applications
- Automotive industry: hardness checks on shafts and castings
- Metalworking and steel construction: hardness testing of sheet metal and structural components
- Energy and power plant industry: on-site testing of plant components
- Oil and gas industry: hardness testing of fittings and pipework
- Aerospace: testing of metal components
The HMM-NP is suitable for inspectors who need a light device (0.25 kg) with tensile strength conversion and do not print out the measured values. Anyone wishing to transfer values to a PC via USB should consider the HK-D or HN-D models.
Technical details
| Measuring method | Leeb, external rebound sensor, type D |
| Measuring range | 170 to 960 HLD |
| Readability (d) | 1 HL |
| Measurement accuracy (Kern) | ± 1 % at 800 HLD (± 6 HLD) |
| Hardness units | HL, HV, HB, HRB, HRC, MPa |
| Tensile strength | 375 to 2,639 MPa (steel) |
| Test object minimum thickness | 3 mm, firmly coupled on a solid base |
| Test object minimum weight | 2 kg with firm coupling |
| Minimum radius of curvature | 50 mm (10 mm with stabilising ring) |
| Measuring probe | Length 14.6 cm, Ø 2 cm |
| Memory | 9 measured values, mini statistics |
| Display | LCD |
| Power supply | 3 AAA batteries (1.5 V), alkaline-manganese, included in the scope of delivery |
| Auto-Off | 3 min |
| Housing | Plastic, 30 x 80 x 150 mm (W x D x H) |
| Net weight | approx. 0.25 kg |
| Factory calibration certificate | can be ordered separately, item no. 961-131 |
| Warranty (manufacturer) | 36 months according to Kern, excluding wear parts |
Scope of delivery
- Sauter HMM-NP Leeb hardness tester (without printer)
- External rebound sensor type D
- Hardness reference block (790 ± 40 HL)
- 3 AAA batteries (1.5 V)
- Carrying case
Calibration
A factory calibration certificate (item no. 961-131) can be ordered separately. A separate factory calibration certificate (item no. 961-132) is available for the hardness reference block.
Warranty
According to Kern & Sohn, this device comes with a 3-year warranty. Kern grants 3 years on products with a list price of €500 or more and 2 years on products below that and on components; wear parts such as batteries and rechargeable batteries are excluded. Warranty repairs are carried out by Kern or by a Kern dealer.
Downloads
Operating instructions Sauter HMM (PDF)Regulatory information
As an electrical device, the hardness tester falls under the ElektroG. The manufacturer Kern & Sohn GmbH is registered under the WEEE registration number DE 80821200. How to return old appliances is described on the page Environment and disposal.
Individual requirements and procurement service
The hardness reference plates AHMO D02 (790 ± 40 HL), AHMO D03 (630 ± 40 HL) and AHMO D04 (530 ± 40 HL), as well as the AHMR 01 support rings, are also available. Enquiries are handled via our procurement service.