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Sentry Express Digital Temperature Controller
6
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SPd4:
Single Segment 4 / 1500°F/833°C rate per hour
SPd5:
Single Segment 5 / Maximum rate
PrO1:
Ramp-Hold, Program 1
PrO2:
Ramp-Hold, Program 2
PrO3:
Ramp-Hold, Program 3
PrO4:
Ramp-Hold, Program 4
(To get back to
IdLE
, press
START/STOP
several times
until
IdLE
appears.)
Temperature Over-Shoot
When a kiln is heated too fast, it may over-shoot the
target temperature, especially in small kilns at lower
temperatures. To avoid this, add an extra segment in a
Ramp-Hold program to slow the firing. The segment
with the slower rate should begin approximately 40° -
60° below the target temperature.
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 program is one segment. You can use up to
eight segments with your controller in Ramp-Hold
mode.
Each segment includes a firing rate and firing tem-
perature. You can also soak, or hold, the temperature for
a specified period. Each segment stores three details:
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
1 - 4.
The first message to appear after you plug in your
Sentry Xpress is
IdLE
. Press
START
. Then use the
Up
Arrow
key to scroll through these messages:
PrO1
PrO2
PrO3
PrO4
SPd1
SPd2
SPd3
SPd4
SPd5
.
To use Ramp-Hold mode for the first time, select
PrO1
.
You do that pressing the
START
key after
PrO1
appears.
Then follow the boxed instructions on page 7 to enter
temperature, heating rate, etc.
PrO1
is Program 1. When you fire the kiln again, you
can repeat Program 1 by selecting
PrO1
. When you are
ready to fire a different program, select
PrO2
, which is
Program 2. Then enter temperatures, heating 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 firing. Often one segment is all you will need. Zero
out the unused segments. The instructions on page 7
explain how to do that.
You can over-write a program by selecting it and
entering new rates and temperatures. This automatically
over-writes the previous program. Write down your pro-
grams in a notebook and record firing results for all fir-
ings.
Repeat Firings
To repeat the last firing, press ENTER from
IdLE
.
The kiln will begin firing. But first, make sure you are
repeating the correct firing by using Program
Review (page 3).
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:
Segment
Rate
°
F/
°
C
Temp.
°
F/
°
C
Hold
1
500/277
1450/788
00.00
2
100/55
700/371
00.00
The first segment is the heating segment. The second
one is the cooling segment. The controller does not use
minus numbers for cooling. Just enter a lower target
temperature 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
temperature quickly by propping the lid but program a
slow cooling rate, the controller will just raise the tem-
perature 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 rap-
idly through the devitrification range. To program a
flash-cool, use maximum rate. This shuts off the heating
elements during 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.
