Humboldt H-3185B Rapid, Freeze Thaw Cabinet - Manual (Page 10)

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5.2 Setting Holdback Band
1) Continuing from section 5.1, while the green display is alternating between
“rOPt” and “8.r.S” as in step 3 of the previous section, push the Mode
button again until the green display reads “HLd.b” (Figure 11). This is the
Holdback Band function. The green display will alternate between “HLd.b”
and the holdback set temperature variance.
Note: The Holdback Band changes the allowed temperature variance from the
set value. If the actual temperature goes beyond this variance during the cycle,
the ramp timer will stop and the controller will attempt to reach the set value
temperature by switching back and forth between heating and cooling until
the set value is reached before continuing. This setting is preset to 2° which is
slightly less than the 3° variance specified by the ASTM standard at the cycle
extremes. Increasing this setting could allow the test sample to exceed the
allowed variance at the cycle temperature extremes. Decreasing this setting
could cause non-uniform cycling temperature changes as well as the overall
cycling time. It is not recommended that this setting be changed.
5.3: Setting Termination State
1) Continuing from section 5.2, while the green display is alternating between
“HLd.b” and “2.0” as in the previous section, push the Mode button again
until the green display reads “tEr.S” (Figure 12). This is the Termination
State function. The green display will alternate between “tEr.S” and “Stby”.
Options for this function are Last Set point “LASt”, Default Set point “dEFt”,
and Standby “Stby”.
2) To change this setting, press the up or down arrow button until the green
display shows the desired setting.
Note: The Termination State tells the controller
what to do at the end of the test. The controller is
preset to go to standby when the testing
is complete.