Sea Technology

FEB 2018

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

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Page 21 of 52 February 2018 | ST 21 and multiple uses of this unit, it is imperative that all specifications are verified. Calibration for Essential Radio Comms For many years, Tra-Cal Lab per- formed calibrations of spectrum analyzers and watt meters for a de- fense contractor that makes truck radio communications systems for the military. Then, one day, the defense contractor's supervisor in charge of sourcing informed Tra-Cal Lab that they would not be renew- ing their service contract. Instead, he had found a mobile lab that was cheaper, faster and performed all their calibrations on site. Tra-Cal Lab educated the sourc- ing supervisor on what to look for in a calibration service by providing them with the manufacturer's pro- cedures, standard turnaround times and equipment requirements for calibration. The defense contractor found that the cheaper service provider was performing a 2- to 4-hour spec- trum analyzer calibration in only 15 minutes. In addition, they used a 2-GHz generator, when a 26.5-GHz generator was required to calibrate the 26.5-GHz spectrum analyzer correctly. Similarly, the 10,000- watt meter, which normally takes 25 minutes to calibrate, was tested in only 5 minutes. The service pro- vider used a 0 decibel (dB) signal in and a power meter and sensor on the other side to measure whether a signal went through. Instead of checking 120 to 150 test points to ensure complete functionality of the equipment, the low-cost provid- er just performed a self-test or just a few test points. The steps performed by the cheaper service provider do not properly measure the unit's 10,000-watt elements capability, let alone 5,000, 1,000 or even 5 watts. Ultimately, Tra-Cal Lab properly calibrated the spectrum analyzers and watt meters. This is an example of how the on-site, faster, low-cost provider is not always the best option. In this case, there is a real risk that uncali- brated spectrum analyzers and watt meters could endanger our military troops who rely on radio communi- cation for their safety. Calibration for Navy Ship Antennas A defense contractor that manu- factures Navy ship antennas began using a low-cost calibration service with a mobile lab. The mobile lab routinely came on site to perform all of their calibration services. They calibrated a permeability meter and provided a calibration sticker and calibration certificate. Permeability meters measure the thickness and conductivity, called the mu factor, of the metal in the antenna to de- termine how the antenna will trans- mit. These antennas may be used to transmit critical communication between the naval base and the ground troops to ensure the troops' safety. Nine years later, the defense contractor sent the permeability meter to Tra-Cal Lab. Tra-Cal Lab told the defense contractor that the meter needed to be sent directly to the manufacturer for calibration because the manufacturer's proce- dures and tools are all proprietary, making it impossible for any other service provider to calibrate the unit. The manufacturer confirmed that the unit could not be calibrated by any other provider and that the unit was so far out of specification that it likely had been out of specifi- cation for four to five years. This is an example of how the convenient, low-cost provider is not always the best option. In this case, there is a real risk that uncalibrated permeability meters could endan- ger our military troops on the front line by preventing communication with the base. Calibration for Multimeters, Micrometers Prior to coming to Tra-Cal Lab, a customer shared that they sent their multimeters and micrometers to a low-cost repair service provid- er. Any time the units needed a re- placement 9-volt battery or a new $1 fuse, the provider would send them a repair quote, charge a repair fee and keep the meter out of com- mission for two weeks. Tra-Cal Lab treats this kind of work as part of the XeosBeacons

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