The Sea Marconi analyses laboratory can be defined, without doubts, among the “front runners” after the results of two inter-laboratory tests (RRT – Round Robin Test or proficiency test) organised by ASTM International (USA).
The first RRT, in which Sea Marconi obtained extraordinary results, compared the quality of 65 laboratories on an international range in performing analytical tests on dissolved gases (DGA). In the second RRT, 87 laboratories were put in a contest in performing different physical-chemical tests (see Table below).
Both Round Robin Tests emphasised an absolute quality and a great competence by the Sea Marconi laboratory, thus confirming its role as international leader in the analytical tests of insulating fluids. For the accredited laboratories such as Sea Marconi’s. these RRT are essential to maintain the accreditation by Accredia (ex SINAL): in this instance obtained by Sea Marconi in February 2009 and extended in November 2010 and recently renewed.
To interpret correctly the data listed below, some information about these inter-laboratory tests is added. The RRT, also designated as proficiency tests, are an instrument ensuring the quality of the laboratories and the results of the analytical results issued. At the end of each RRT an evaluation is provided by a score system designated as “Z score”, the more this score is near to zero the better is the operation of the laboratory.
As a conclusion, in both the RRT the Sea Marconi laboratory has provided a great proof of force, by obtaining excellence scores both in absolute terms and in comparison with the laboratory worldwide.
Please find here below the results of the Proficiency test.
| Evaluation of tests on dissolved gases (DGA) | |||||||
| PT | Parameter | Results SMT | Average value PT | UdM | Z-Score | Result | Accreditated test YES/NO |
| ASTM PTP DGA1108 | Nitrogen | 73014 | 60461 | ?l/l | 1,3 | Satisfactory | YES |
| Oxygen | 36180 | 28179 | ?l/l | 1,5 | Satisfactory | YES | |
| Carbon dioxide | 1477 | 1455,4 | ?l/l | 0,1 | Good | YES | |
| Carbon monoxide | 11 | 10,9 | ?l/l | 0 | Good | YES | |
| Hydrogen | 2 | 4,4 | ?l/l | -0,8 | Good | YES | |
| Methane | 10 | 10,5 | ?l/l | -0,2 | Good | YES | |
| Ethane | 63 | 59,6 | ?l/l | 0,5 | Good | YES | |
| Ethylene | 37 | 34,6 | ?l/l | 0,6 | Good | YES | |
| Acetylene | 14 | 12,5 | ?l/l | 0,4 | Good | YES | |
| Propane + propylene | 2 | 0,5 | ?l/l | 1,4 | Satisfactory | YES | |
| Insulating Fluid Quality – Evaluation of the physical- chemical tests | |||||||
| PT | Parameter | Results SMT | Average value PT | UdM | Z-Score | Result | Accreditated test YES/NO |
| TM PTP IFQ1109 | Acidity | < 0,01 | 0,009 | mg/g | -1,7 | Satisfactory | NO |
| Colour ASTM | 0,5 | < 1,0 * | – | – | Good | NO | |
| Corr. Sulfur D 1275 A | 1b | 1b * | – | – | Good | NO | |
| Corr. Sulfur D 1275 B | 1b | 1b * | – | – | Good | NO | |
| 2-FAL | 1 | 1 | ?g/kg | 0 | Good | YES | |
| 2-FOL | assente | assente | ?g/kg | 0 | Good | YES | |
| 5-MEF | assente | assente | ?g/kg | 0 | Good | YES | |
| 5-HMF | assente | assente | ?g/kg | 0 | Good | YES | |
| 2-ACF | assente | assente | ?g/kg | 0 | Good | YES | |
| IFT | 41,5 | 44,33 | mN/m | -1 | Good | NO | |
| DBPC | 0,36 | 0,287 | % m/m | 1,4 | Satisfactory | NO | |
| Particles > 4 ?m | 307 | 399,77 | n°/ml | -0,2 | Good | NO | |
| Particles > 6 ?m | 71 | 109,19 | n°/ml | -0,4 | Good | NO | |
| Particles > 14 ?m | 7 | 11,86 | n°/ml | -0,5 | Good | NO | |
| Pour Point | -63 | -56,1 | °C | -1,8 | Satisfactory | NO | |
| Density | 0,8877 | 0,89315 | g/ml | < -3 | Unsatisfactory | NO | |
| Kinematic viscosity 40°C | 9,37 | 8,865 | cSt | > 3 | Unsatisfactory | NO | |
| Water in oil | 27 | 36,8 | mg/kg | -2,2 | Questionable | YES | |
* mode (most frequent value)
Among the 28 tests under exam, only the parameters for density and kinematic viscosity didn’t obtain Z scores complying with the majority of the participating laboratories.
To investigate the causes of this discrepancy, the laboratory has already implemented the internal quality procedures that shall result shortly in a corrective action. The tests for water, having a questionable result, shall be soon under evaluation again, thus more elements on this subject are going to be obtained. All the other Z scores have pointed out a great professionalism by the Sea Marconi laboratory, with points of excellence in the determination of gases and furans.
