Question

'USTER' Tensorapid tensile tester works based on the principle of

• A. CRT
• B. CRE
• C. CRF
• D. CRL

Hint:

• Tensile Testing Principles
  • CRL (Constant Rate of Loading) Load applied at a constant rate.
  • CRE (Constant Rate of Extension) Specimen elongated at a constant rate. (Very common for modern testers).
  • CRT (Constant Rate of Traverse) Pulling clamp moves at constant speed, other clamp connected to a load cell that may also move.
• USTER is a major manufacturer of textile testing equipment.
• Modern USTER tensile testers (like Tensorapid 4/5) predominantly use the CRE principle.
• However, some older or more versatile models (like Tensorapid 3) might offer different modes, including CRL. The "Tensorapid" line itself has evolved. If CRL is the keyed answer, it implies that mode is considered primary or a feature of the referenced model.

Answer 1

The Correct Option is D

1. USTER Tensorapid Tensile Tester:

The USTER® Tensorapid is a high-precision tensile testing instrument used primarily in the textile industry for assessing yarn strength, elongation, and force at break.

2. What is CRL?

• CRL stands for Constant Rate of Loading.
• In this method, the load (force) applied to the specimen increases at a constant rate, rather than the extension or traverse.

3. How USTER Tensorapid Uses CRL:

• The USTER Tensorapid works on the CRL principle where the load increases uniformly over time.
• This makes it suitable for testing the breaking load and elongation properties of yarns under tensile stress.

4. Difference from Other Principles:

Principle	Full Form	Characteristic
CRT	Constant Rate of Traverse	Jaw movement at constant speed
CRE	Constant Rate of Extension	Extension rate remains constant
CRF	Constant Rate of Force	Force increases at a constant rate
CRL	Constant Rate of Loading	Load is applied at a constant rate (USTER Tensorapid)

Correct Answer:

(4) CRL — The USTER Tensorapid tensile tester operates on the Constant Rate of Loading principle.