U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

HHS:PHS:FDA:CFSAN:OC:DCP:MSB
 
                                              200 C Street, SW
                                              Washington, DC 20204
 
                                                  November 27, 1991
 
                                                  M-b-314
 
TO:       All Regional Food and Drug Directors
          Attn:  Regional Milk Specialists
 
FROM:     Milk Safety Branch (HFF-346)
 
SUBJECT:  Digital Reference Thermometer (DRT) Mfg. by Anderson
Instrument Co.
 
 
The above subject dairy equipment has been reviewed by Milk Safety
Branch and Food Engineering Branch and found to comply with the
applicable criteria to permit the use of the DRT as a replacement
for the mercury actuated indicating thermometer required on holding
tubes of HTST or HHST pasteurization systems.
 
The DRT has been tested by food Engineering Branch and found to be
equally failsafe, accurate, reliable and meet the scale and
thermometric response specifications of Appendix H of the Grade 'A'
Pasteurized Milk Ordinance.
 
The DRT provides for failsafe operation by utilizing two separate
resistance temperature devices (RTDSs). If the two RTDs read more
than 0.5oF difference from one another the display blanks making it
impossible for the operator to observe the temperature.  This
condition, as with a broken mercury actuated thermometer, would
require the immediate replacement of the thermometer.
 
The conventional test of Appendix I for Indicating Thermometers
(Test 1 and 7) should be run on the DRT.  The instruction manual
supplied with the DRT provides additional guidelines for performing
these tests.  After testing by the regulatory agency they should
apply their conventional seal to the cover and to the head of the
dual element temperature sensor to assure that the sensor has not
been replaced which would entail retesting of the instrument.
 
Descriptive literature for the dairy equipment is included for your
files.  States desiring further information or copies of the
literature may contact:
 
                     Anderson Instrument Co.
                     RR 1, Auriesville Road
                     Fultonville, NY  12072
 
Sufficient copies of this memorandum are enclosed for distribution
to state milk control agencies and state milk sanitation rating
officers in your region/district.
 
FDA's review of this dairy equipment and our finding that they
comply with the applicable construction criteria of the Grade "A"
Pasteurized Milk Ordinance does not constitute agency endorsement
or approval of the dairy equipment and any representation on a
label or in any printed literature that they are "FDA approved"
would be false.
 
 
 
 
                                   Robert L. Sanders
                                   Deputy Chief,
                                   Milk Safety Br.
{PB