public function calculateLam(Crystal $crystal)
 {
     $sEnv = $crystal->getEnvironment();
     $piE = $this->systemService->getPiE(191, $sEnv);
     $base = 0.013 * pow($crystal->getFrequency(), 0.23);
     $qual = $crystal->getQuality();
     if ($qual == "MIL-SPEC") {
         $piQ = 1;
     } else {
         $piQ = 2.1;
     }
     $lambda = $base * $piQ * $piE * pow(10, -6);
     return $lambda;
 }