Carrier PrimeLINE 69NT40-561-200, Operation And Service Manual

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4–57 T-362
4.6.8 USDA Cold Treatment
Sustained cold temperature has been employed as a post-harvest method for the control of fruit flies and other
insect genera. The commodity, insect species, treatment temperatures and exposure times are found in sections
T107, T108, and T109 of the USDA Treatment Manual.
In response to the demand to replace fumigation with this environmentally sound process, Carrier has integrated
Cold Treatment capability into its microprocessor system. These units have the ability to maintain supply air
temperature within one quarter degree Celsius of set point and record minute changes in product temperature
within the DataCORDER memory, thus meeting USDA criteria. Information on USDA is provided in the following
sub-paragraphs.
USDA Recording
A special type of recording is used for USDA cold treatment purposes. Cold treatment recording requires three
remote temperature probes be placed at prescribed locations in the cargo. Provision is made to connect these
probes to the DataCORDER via receptacles located at the rear left-hand side of the unit. Four or five receptacles
are provided. The four 3-pin receptacles are for the probes. The 5-pin receptacle is the rear connection for the
Interrogator. The probe receptacles are sized to accept plugs with tricam coupling locking devices. A label on the
back panel of the unit shows which receptacle is used for each probe.
The standard DataCORDER report displays the supply and return air temperatures. The cold treatment report
displays USDA #1, #2, #3 and the supply and return air temperatures. Cold treatment recording is backed up by a
battery so recording can continue if AC power is lost.
USDA / Message Trip Comment
A special feature in DataLINE allows the user to enter a USDA (or other) message in the header of a data report.
The maximum message length is 78 characters. Only one message will be recorded per day.
USDA Cold Treatment Procedure
The following is a summary of the steps required to initiate a USDA Cold Treatment. If configured for USDA
probes, setup can be verified as follows. This procedure is applicable for DataLINE software.
1. Ensure the DataCorder is configured as follows from the Configuration Screen (see
Figure 4.9
):
a. Configuration Option is set for USDA probes.
b. Logging Interval is set for 60 minutes.
c. DataCorder Sample Type is set for 2 Averaged 3-USDA.
d. Resolution is set for Normal.
Figure 4.9 DataCORDER Configuration Screen