With a special high accuracy testing device like Legatest, yes, of course!

Legatest electronic system is made from high quality components to maintain adequate measurement properties at variable temperatures of use.

By keeping the requirements of the standard EN ISO 4126-1:2013, chapter 7.2.3: »The uncertainty of pressure measurement shall be within +- 0,5 % in the temperature range between -15°C up to 60°C.«. How is it possible?

With an innovative approach to some limitation overcome:

By measurement uncertainty automatic determination

According to L-PLAN Legatest procedure P11;5.4.11 Analysis and procedure for measurement uncertainty calculation meet requirements from EURAMET, DKD, EA…,.

Legatest system and software includes function of measurement uncertainty automatic calculation, based on:

  • Used measurers and measurers chain influences
  • Environmental influences
  • Testing influences
  • Measuring influences: resolution, force increasing speed…
  • Middle seat diameter error regarding on real sealing is taken into account.

Legatest electronic and environmental temperature are monitoring via temperature sensors also to avoid the testing out of the temperature range.

Temperature validation (document RA11; 5.4.10 Legatest validation report) was performed and accepted by Slovenian Accreditation institute (member of International Laboratory Accreditation Cooperation) according to international standard EN ISO/IEC 17020, which shall be implemented in L-PLAN Company like Conformity Assessment – Inspection body and manufacturer of device Legatest.

Also between different laboratories comparisons are periodically done.

By force measurement chain accuracy compensation:

Force sensors and Legatest force electronic calibration resultants can be promptly compensated by calibration correction factors.

With an innovative approach in the introduction of testing methods during operation.

  • The Legatest device protection functions
  • The safety valve and process pressure systems protection functions
  • Several monitoring functions

With a daily using the Legatest device for on-line safety valve testing like Conformity Assessment – Inspection body since 1996!

On-site safety relief valves testing can be very accurate also because of it is performed in real process pressure equipment operating conditions which are safety valves exposed:

  • Process system temperature
  • Accumulation and flow capacity
  • Compliance of the back pressure
  • And other process pressure equipment performance influences.


  • The results are reproducible and cannot be manipulated.
  • Reports generated all relevant input data, test results and the respective diagrams, testing time and date.
  • The readjustment of opening pressure can be done easily.

This method is used more than 30 years.

With a very good knowledge of the operation of safety valves and process pressure equipment:

L-PLAN is Accredited Conformity Assessment Body – Inspection Body in the field of Pressure Equipment, as same as safety and other valves Testing / Inspection and pressure gauges Testing / Inspection.

Since 1991, Inspection, testing experiences are successfully included into the innovative development and production of measurement, test, calibration and inspection devices as same as methods and procedures.

1992 L-PLAN was the first in the world with the Safety Valve Data Acquisition Testing System.

We and also many clients are using the Legatest series devices every day. So the L-plan developed devices are constantly being improved.

We don’t produce the test units serial!

We try to adapt your requirements, ideas and specifics pressure equipment working roles.

Legatest on line testing device has several approvals. In addition to the device certification particularly is very important also on-line testing method approval.

See on line safety valves testing device Legatest approvals…

More about On-line pressure safety valves testing ….

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