FOOTNOTES TO TABLE III-l 



(1) The former "ACF" instrument is now made by: NUS Corporation, 

 Underwater Systems Division, Hackensack, New Jersey. Tel: 201-265-2400. 



(2) NUS ("ACF") make two types, TR-3 and TR-4. The TR-3 is shorter but 

 its sound path is determined by the dimensions of a bulkhead of 

 stainless steel and a temperature and pressure correction is hence 

 required. The TR-4, the later model, defines the path by three 

 freestanding Invar rods and therefore has practically no temperature 

 or pressure error. 



(3) According to the manufacturer, the Navy Oceanographic Office, Instru- 

 mentation Center, issues a Fact-sheet (1FS-001-64) in which they state: 



"The relationship between the sound velocity (C) , and the 

 "Sing-Around" frequency (F) , as stated by the manufacturer is: 

 C = .205916F ±.15 m/sec. This equation was observed to result 

 in an error of ±.31 to -.05 m/sec. However, if the relationship 

 for this particular instrument is changed to : C = . 206451F - 

 3.96 m/sec, the error is within ±.1 m/sec." 



(4) Made by Ramsay Engineering Company, 707 North Anaheim Boulevard, 

 Anaheim, California, Tel: 714-774-5511. 



(5) The Navy Oceanographic Office, Instrumentation Center, tested this 

 instrument (Reference 32) and issued a fact-sheet (1FS-006-66) in 

 which they state: 



"The relationship between sound velocity (C) and the 

 sing-around frequency (F) as stated in the manufacturer's 

 specifications is C = 0.5 F. Using the MK-V Deep Sea Probe, 

 sound velocity measurements were made in distilled water for 

 the temperature range of 0°C to 30°C. Comparison of test 

 results with standard values (Martin Greenspan and Carroll E. 

 Tschiegg, "Speed of Sound in Water by a Direct Method," 

 Journal of Research of the National Bureau of Standards, 59:4 



30 



Srthur ZD.lUttle.2lne. 



