Calibration Of Electronic Weighing Equipment

Calibration of electronic weighing equipment for accreditation purposes comprises the following instruments:
  • Electronic, non-automatic scales with Max capacity up to 3000 kg;
  • Electronic automatic scales with Max capacity up to 60 kg;
  • Scales/electronic comparators with Max capacity up to 25 kg.
Standard calibration of non-automatic scales includes:
  • estimation of errors of indication (systematic error) measured in maximally 5 testing points;
  • estimation of repeatability parameter (random error expressed by standard deviation);
  • estimation of errors being an effect of eccentric loading;
  • estimation of errors of indication (systematic error) wherein the TARE device operates;
  • issuing the Calibration Certificate.
Standard calibration of automatic scales includes:
  • estimation of static errors (static error of indication, repeatability expressed as a standard deviation, errors being an effect of eccentric loading);
  • estimation of dynamic errors (standard deviation estimated using tested sample);
  • issuing the Calibration Certificate.
Assessment of conformity with requirements of the following documentation is possible:
  • Directive 2014/31/EU of 23 February 2014 on non-automatic weighing instruments;
  • Assessment of conformity with requirements specified by the client.
Calibration of mass standards and weights for accreditation purposes includes:
  • Mass standards and weights of E1 class from 1 mg to 500 mg;
  • Mass standards and weights of E2 class from 1 mg to 1 kg;
  • Mass standards and weights of F1, F2, M1, M2 and M3 classes from 1 mg to 1000 kg;
  • Mass standards of 25 kg;
  • Weights from 1 to 20 kg.
Mass standards calibration comprises both, estimation of mass standard weight with expanded uncertainty and issuing the Calibration Certificate. Additionally mass standards adjustment is also possible (ie. setting the mass standard close to permissible error limits for a given class or close to tolerance limits specified by the client – if only this is technically possible) as well as assessment of compliance with requirements specified by the ordering party.
Calibration of automatic piston pipettes for accreditation purposes includes:
  • Adjustable and fixed volume pipettes from 1 µl to 10 000 µl.
Calibration is carried out via gravimetric method in accordance with requirements of standard ISO 8655-6. Calibration certificate may contain results of calculation of errors determined by standard ISO 8655:
  • Systematic error es – determined in [µl] and [%];
  • Random error – determined as standard deviation Sp in [µl] and CV in [%].
Piston pipettes calibration includes estimation of pipettes indication error for a tested volume together with expanded uncertainty and issuing the Calibration Certificate. Traceabilty is refered to standard of a measuring unit through using electronic balances (micro analytical) which are certified with the Calibration Certificate issued by an accredited calibration laboratory, wherein the certificate is valid. The balances meet metrological requirements determined for gravimetric method by standard ISO 8655-6.
Following the Good Manufacturing Practice rules it must be proved that using the same materials and equipment guarantees manufacturing products of the same quality. Validation of equipment is a recommended and effective way to meet any procedural requirements.
 
Radwag company as a renowned manufacturer of balances and scales offers validation of the weighing equipment. The offer is mainly intended for pharmaceutical industry clients. Within the scope of the offer there is documentation preparation and RADWAG representative assistance while performing the particular steps of the process, ie.:
 
Instalation Qualification (IQ) – a process during which it is controlled whether the balances/scales and weighing systems have been installed in compliance with the clients demands and the manufacturers documentation. The documentation is examined as well.
 
Operational – Performance Qualification (OQ – PQ) – a process during which efficiency of a balance/scales or weighing system is controlled and checked in terms of correct operation according to declared specification and adopted criteria for acceptance.