There is a company located in Chicago that Mfg. Ultrasonic and Impact Echo test equipment. I can give you the phone number but not sure who you would speak with. Hopfully this is ok. The phone number is 773-463-6565. Good luck with your project.
WHEN TALKING WITH PEOPLE OVER THE LAST FEW YEARS I HAVE BEEN TOLD THAT MAKING TEST CUBES ALONG WITH CHECKING THE INPLACE STRENGTH USING THE ASTM C803 RESISTANCE TO PENETRATION PIN TYPE IS A GOOD WAY TO ENSURE THE QUALITY OF THE MORTAR AT THE JOB SITE.