Ramp-Hold Mode; Programming A Cooling Segment - Orton Sentry Xpress Sentry Xpress 4.0 Manual

Ramp-Hold
Mode
You can make your own firing programs and store them
in the controller's memory. A firing program tells the kiln
how fast to fire, and to what temperature. The simplest pro-
gram is one segment. You can use up to 8 segments with
your controller in Ramp-Hold mode.
Each segment includes a firing rate and firing tempera-
ture. You can also soak, or hold, the temperature for a spec-
ified period.
The Parts of a Segment
Rate (temperature change in degrees per hour)
Target temperature
Hold at the target temperature (not always used)
The controller can retain four programs in memory even
when power is turned off. Programs are numbered Pro1 -
Pro4.
The first message to appear after you plug in your Sentry
Xpress is . Press
to scroll through these messages:
To use Ramp-Hold mode for the first time, select
. You do that by pressing the
appears. Then follow the boxed instructions on page 8 to
enter temperature, heating rate, etc.
is Program 1. When you fire the kiln again, you
can repeat Program 1 by selecting
When you are ready to fire a different program, select
, which is Program 2. Then enter temperatures, heat-
ing rates, etc. Select Program 3 and 4 the same way.
A program can have up to 8 segments, but you don't have
to use all 8 segments. Use only the number needed per fir-
ing. Often one segment is all you will need. Zero out the un-
used segments. The instructions on page 8 explain how to
do that.
To over-write a program, select it and enter new rates
and temperatures. This automatically over-writes the previ-
ous program. Write down your programs in a notebook and
record firing results for all firings.
Programming a
Cooling Segment
For controlled cooling, program a segment to a lower
target temperature than that of the preceding segment.
Example: You fire at a rate of 500°F per hour to 1450°F
with your first segment. You want the kiln to cool at a rate
of 100°F per hour down to 700°F. Here is how you would
program the two segments:
. Then use the
.
key after
. (See page 4.)
Segment
1
2
The first segment is the heating segment. The second
one is the cooling segment. The controller does not use mi-
nus numbers for cooling. Just enter a lower target tempera-
ture than that of the previous segment.
If you prop the lid or door for a fast cooling, program a
fast cooling rate for that segment. If you lower the tempera-
ture quickly by propping the lid but program a slow cooling
rate, the controller will just raise the temperature again.
Example: Some glass artists flash-cool the glass just after
it fuses. They open the door a few inches to remove heat,
then close it again. This takes the glass down rapidly
through the devitrification range. To program a flash-cool,
use maximum rate. This shuts off the heating elements dur-
ing that segment, allowing the kiln to cool rapidly.
Note: During fast cooling, do not open the door all the
way. Do not force-cool the kiln with a fan.
Note: You may get an FTL error message (page 12) if
you program a cool-down target temperature that is
key close to room temperature. This is because the kiln
cools more slowly as it approaches room temperature,
causing the error code.
A Ramp-Hold
Practice Program
To practice using the controller, we will enter a program
that includes three segments. The last segment is a cooling
segment.
Using the programming instructions on the next page,
enter this firing schedule. Then use Program Review (page
4) to check for accuracy.
Make a simple chart like the one above when planning a fir-
ing program.
PrO1
rA1 = 250
°F 1 = 750
HLd 1 = 00.00
rA2 = 900
°F 2 = 1425
HLd 2 = 00.30
rA3 = 150
°F 3 = 750
HLd 3 = 00.00
rA4 = 0000 (zeroes cancel segments 4-8)
Rate Temp.
°F/°C °F/°C
500/277 1450/788
100/55 700/371
Hold
00.00
00.00
7