Sentry Industries Sentry 2.0 Slow Cooling Cool, When the Kiln Shuts Off Too Soon

Watch the pyrometric witness cones through the peep- hole. Press STOPwhen the correct witness cone bends, not- ing how much Hold time was needed. Program that much Hold time the next time you fire the same type of ware loaded to the same capacity.

Note: During Hold, the display temperature will alternate with time left in Hold. To figure hold time for the next firing, subtract time left in Hold from the total Hold time entered.

When Hold is set to 99.99 hours, the Sentry will remain at that temperature indefinitely, until STOP is pressed.

Slow Cooling (COOL)

Slow cooling enhances the quality of some ceramic glazes. Slow cooling encourages crystal develoment, deeper gloss, and sometimes startling color shifts. Iron red glazes seem to respond well to slow cooling. For these reasons we have added a Slow Cooling feature to Cone-Fire.

■Slow Cooling begins after the cone firing (and Hold, if any) and ends at 392°F/200°C.

■When COOL appears in Cone-Fire programming, enter a cooling rate between 1°F/C to 180°F/82°C. A good start- ing point is a rate of 90°F/50°C.

■Enter a rate of 0 to turn Slow Cooling off.

Note: Slow Cooling can extend the firing time by many hours. For instance, if the shutoff tempera- ture is 1945°F/1063°C, and the cooling rate is 100°F/55°C, the kiln will take 15 ½ hours to reach 392°F/200°C.

When the Kiln Shuts Off Too Soon

If the kiln shuts off before the pyrometric witness cone bends, you can turn the kiln back on and keep firing. Simply program the next hotter cone in Cone-Fire. Then from IdLE , press START. The kiln will begin firing, taking up where it left off.

Note: By looking at the witness cones through a peephole, you will know if the kiln shuts off too soon.

If the kiln shuts off within 100°F/55°C of maturity, and the temperature drops 50°F/28°C or more after the kiln shuts off, do not depend on the witness cones. Once they cool 50°F/28°C after they have been heated to within 100°F/55°C of maturity, they will not bend properly. This is because they form a hard shell.

Wrong Thermocouple Type

If a Type-K thermocouple is installed on your kiln, but your controller is set for Type-S, the kiln will continually underfire by a wide margin. See page 19 to check thermo- couple type.

For Kilns with AOP Outlet

The AOP (auxiliary output) is a special-order receptacle mounted in the kiln switch box. The Sentry controls power to the AOP receptacle. The AOP is usually used to power a kiln vent.

The Fan option, which is accessed through the OPTIONS key, determines when an AOP-powered kiln vent will oper- ate during Cone-Fire.

Before the Fan option will appear on the Options list, (1) you must enter a Cone-Fire program in active memory and

(2)you must select FAN3 in the AOP option. (See page 20 for instructions on selecting FAN3 in the AOP option.)

1From IdLE , press OPTIONS repeatedly until FAN appears.

2Press ENTER. Use the 1 and 2 keys to select one of these settings:

■ON The vent is on during Pre-Heat, the cone firing, and Slow Cooling. It turns off at 212°F/100°C.

■OPT The vent is on during Pre-Heat and the cone fir- ing. It is off during Slow Cooling.

■OFF The vent is off all the time.

3After selecting one of the above, press ENTER. Press STOP to return to IdLE .

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