MARCH 2007

Inspecting and Testing Electronic Carcass Evaluation Devices 

By Dick Suiter 

This is the fourth in a series of W&M Quarterly articles intended to familiarize weights 

and measures field officials and administrators with electronic carcass evaluation device 

standards, operation, inspection, and testing. Previous articles (November 2005, June 

2006, and September 2006 editions) may be found on the WMD website at 

http://ts.nist.gov/WeightsAndMeasures/newsletterarchive.cfm. 

This article and subsequent articles in the series will describe additional devices or 

systems currently in use commercially and others currently being used in noncommercial applications, but which have the potential of commercial use. For each 

device or system the articles will provide an overview of the base technology utilized and 

how the equipment functions, as well as test methods and reference material or physical 

standards currently available for use in conducting accuracy verification. 

In this article we will look at the Ultra FomTM (Figure 1) built by SFK Technology, Inc., 

and the handheld ultrasonic unit built by Animal Ultrasound Services (AUS) (Figure 2). 

These handheld devices utilize ultrasonic energy of sound waves for measuring back fat 

and depth of the loin eye. 

 

 

 Figure 1 

 Figure 2

The Ultra FomTM uses an array of 64 ultrasound transducers to measure fat and lean meat 

thickness over a 5-cm-wide cross section near the centerline and the 3rd and 4th ribs next 

to last rib of the carcass. From those measurements the Ultra FomTM provides a display 

on the device of the thickness of fat over a range of 5 mm to 30 mm and the thickness of 

muscle over a range of 30 mm to 80 mm at the measurement point. From those 

measurements the device can also calculate and display the percentage of lean meat for 

the carcass measured. 

The AUS device uses similar technology with approximately 100 measuring elements 

that make up the measuring surface of the device. The AUS device provides a two 

dimensional image of the measurement on the device as shown in figure 3. The system 
also provides a digital display of the measurement of fat, lean, and lean percent on an 

indicator adjacent to the measurement station on the carcass line. 

Figure 3 

Testing of these devices is a relatively simple process of conducting linear measurements 

using a “calibration standard.” 

An example of a test standard developed by one of the manufacturers is shown in Figures 

4 and 5. This test block is made of a temperature-stable material and is intended to 

provide measurements very similar to those taken from an actual carcass. 

 Figure 4 Figure 5 

The United States Department of Agriculture (USDA) performs tests of the device by 

placing the standard on the measuring face of the handheld unit and comparing the 

readings shown on the display with the calibrated values for the test block. This 

procedure verifies both accuracy and repeatability 

Similar, but more detailed test procedures for the handheld ultrasonic devices have been 

developed by one of the manufacturers and a ballot for adding this test procedure to 

ASTM Standard-F2343-061 will be posted later this spring. 

If these devices are used commercially, the device user is required to maintain a test 

standard with the device and is required to perform this procedure at the beginning of 

each production day. Weights and measures officials may elect to witness the daily 

testing on a periodic basis or may choose to conduct their own test using either their own 

standards or the standards maintained on site by the device user. The standards 
maintained on site by the device user are required to meet NIST Handbook 44, Appendix 

A, Fundamental Considerations, Section 3. Testing Apparatus. The user of the device is 

also required to have the accuracy of the test standard verified on an annual basis for 

traceability to a national standard. 

Look for subsequent W&M Quarterly articles in this series for information on other 

technologies used to make measurements of various carcass constituents. For further 

information or questions related to this article, contact Dick Suiter (NIST) by e-mail at 

rsuiter@nist.gov or by phone at 301-975-4406. 

NOTE: 1For referenced ASTM standards, visit the ASTM website, www.astm.org, or 

contact ASTM Customer Service at service@astm.org.