At STEP Lab, extensometers are a key solution for accurately measuring the deformation of materials under load. These instruments are essential for collecting data during materials testing, ensuring accurate results that comply with industry standards. Epsilon Tech’s extensometers can be divided into contact and non-contact types, each with specific applications and advantages.
Contact extensometers
Non-contact extensometers
This mix of options ensures that STEP Lab can offer customers the right extensometer for their various testing needs, taking advantage of the high quality and precision of Epsilon Tech’s solutions.
The new Model 3742 is a clip-on extensometer with automatic gauge length setting, designed for fast and repeatable specimen mounting without gauge pins required. With its innovative Quick-Swap system, gauge lengths can be changed in seconds without tools. This new extensometer is built for high precision and maximum productivity, making it ideal for laboratories that need frequent specimen and gauge length changes.
Features
Specifications
Options
| Contact extensometers | Non-contact extensometers | |
|---|---|---|
| Application | Economical solution for standard applications | Easily adaptable to different test applications |
| Specimen | Inherently rigid samples | All, including highly sensitive samples and those with a high breaking energy. |
| Temperature | Up to 100°C | Up to 40°C |
| Operation | Manual | Automatic: no operator influence, high reproducibility of test results |
Epsilon contact extensometers are designed for reliable performance under a wide range of test conditions. They offer variable output depending on the model and accuracy according to ASTM and ISO standards. They operate over a wide temperature range and are equipped with ultra-flexible cables for easy integration into test systems. The quick-attach kit facilitates mounting on samples of different sizes, making them suitable for different measurements.
Features
Technical Specifications
| Parameter | Value |
|---|---|
| Power Supply | Recommended from 5 to 10 VDC, 12 VDC or VAC max. |
| Output | From 2 to 4 mV/V, nominal, depending on the model. |
| Accuracy | Standard configurations meet ASTM E83 class B-1 accuracy requirements for gauge lengths ≥20 mm and class B-2 for <20 mm. All standard configurations comply with ISO 9513 class 0.5. A test certificate is included. |
| Linearity | ≤0.15% of full scale range. |
| Temperature Range | Standard (-ST): from -40 °C to +100 °C (from -40 °F to 210 °F). |
| Cable | Integrated ultra-flexible cable, standard 2.5 m (8 ft). |
| Standard quick-attach kit |
|
| Operating force | Depends on model configuration; typically from 10 to 100 g. |
Optical, or non-contact, extensometers use advanced optical sensors to measure material deformation, offering an ideal alternative in harsh environments or with complexly shaped samples. The Epsilon ONE® is characterised by its high accuracy, conforming to ISO and ASTM standards, and its ability to operate in real time up to 3000 Hz. Thanks to the laser alignment system and telecentric lenses, it guarantees precise measurements even during out-of-plane movements, making it suitable for a wide range of materials testing applications.
Features
Technical specifications
| Parameter | Value |
|---|---|
| Field of view | 52-500 mm. See specific optical packages; contact Epsilon for other options. |
| Working distance | 150-300 mm typical. See specific optical packages; contact Epsilon for other options. |
| Real-time data transmission rate | 300-3000 Hz, >2000 Hz typical. Includes image frame rate, analysis, analog, and digital output. |
| Analog output | ±10VDC typical, with short-circuit protection. Unit and range selectable. Includes a 2.4 m (8 feet) shielded output cable with a test equipment connector. |
| Digital output | 16-64 bit at >2000 Hz typical, via RS232. Includes a 1.8 m (6 feet) shielded null modem cable. |
| Resolution | <0.5 µm quasi-static, <2.5 µm dynamic, <0.1 µm drift; typical RMS resolution with typical settings. Resolution is a function of optical and filter settings. For more details, refer to the Guide. |
| Extensometer class | ISO 9513 Class 0.5 and ASTM E83 Class B-1 or better typical at ≥10 mm gauge length. |
| Absolute accuracy (PT models) | <±1 µm or 0.5% of value, no greater than ±30 µm typical. |
| Absolute accuracy (CE models) | <±1 µm or 0.5% of value. |
| Thermal drift | Ambient temperature stability <0.002%ε/°C (20 µε/°C). |
| Minimum sample size | < Ø20 μm (0.001"). |
| Gauge length | 2 mm minimum, sample width or diameter ≥4x is recommended. For gauge lengths <10 mm, contact Epsilon. |
| Maximum elongation | >1000%, limited by the field of view and gauge length. |
| Maximum tracking speed | >1500 mm/s (90,000 mm/min). |
| Cyclic testing | >100 Hz typical cyclic test frequency, independent of waveform. |
| Strain control | Suitable for monotonic and cyclic strain control applications. |
| Out-of-plane sensitivity | Out-of-plane motion allowed for ISO 9513 Class 0.5 @15 mm gauge length and ASTM E83 Class B-1: <1000 µm (0.040") for ONE-PT-xx <25 µm (0.001") for ONE-CE-xx. |
| Power supply | 100-240 VAC, 50-60 Hz, 100 W, IEC 320 C14 socket. Specify plug type when ordering. |
| System environment | 10-40°C (50-100°F), for use and storage; 20-80% relative humidity in non-condensing environments. |
| Host PC (optional) | Requires a PC with Windows 7 or 10, minimum 900×550 display, serial or USB port. |
Advantages
With an exclusive focus on the design and production of strain gauges and calibrators, Epsilon has established itself as the leading choice for testing laboratories worldwide.
The Epsilon product range has 36 different models of extensometers with thousands of variants, providing an optimised solution for almost all testing methods, which can also seamlessly integrate with all STEP Lab testing machines and other components for proper operation and reliable results. At STEP Lab, we focus on accuracy and repeatability, ensuring that our systems exceed all industry requirements.
