Lake Shore Model 331 Temperature Controller User’s Manual
Band
Band 2 K* -
2 K* -
100 K
100 K
100 K -
100 K -
305 K
305 K
305 K -
305 K -
375 K
375 K
11
±0.25 K ±0.5 K
±1.0 K
11A
±0.25 K
±1% of Temp.
12
±0.5 K
±1.0 K
±2.0 K
12A
±0.5 K
±1% of Temp.
13
±1 K
±1% of Temp.
Lake Shore Silicon Diode
Temperature Sensor
Standard
SoftCal
Calibration
Precision
Calibration
Standard sensors are interchange-
able within published tolerance
bands. Below is a list of Standard
Curve 10 DT-470 Tolerance
(Accuracy) Bands.
A Lake Shore SoftCal applies only to
Silicon Diodes. A 2-point SoftCal
takes data points at 77.35 K and
305 K. A 3-point SoftCal takes data
points at 4.2 K, 77.35 K, and 305 K.
Lake Shore precision calibrates
most sensor types by taking up to
99 data points concentrated in
areas of interest. Typical silicon
diode calibration accuracy is listed
below.
A Precision Option can be
generated for either SoftCal
or the Precision Calibration:
Precision
Option
Regarding accuracy, there are 3
things that can be done with a
temperature sensor:
8001-331
8000
8002-05-331
Factory installs a NOVRAM
with Precision Option
breakpoint pairs loaded in it.
Users download Precision
Option breakpoint pairs in ACSII
format from a floppy disk.
Users install a NOVRAM
with Precision Option
breakpoint pairs loaded in it.
To increase accuracy, perform a
SoftCal with the controller and
sensor. After sensor calibration, the
custom sensor curve replaces the
standard Curve 10.
* Temperatures down to 1.4 K only with
a Precision Calibrated Sensor.
User calculates break-
points and manually enters
data into the controller
Enter voltages at the 2 or 3 data
points into SoftCal capable
controllers. A calibration report
comes with the sensor.
±1.0 K
2 K to <30 K
±0.25 K
30 K to <60 K
±0.15 K
60 K to <345 K
±0.25 K
345 K to <375 K
±1.0 K
375 K to 475 K
Typical 2-Point Accuracy
Typical 2-Point Accuracy
±0.5 K
2 K to <30 K
±0.25 K
30 K to <60 K
±0.15 K
60 K to <345 K
±0.25 K
345 K to <375 K
±1.0 K
375 K to 475 K
Typical 3-Point Accuracy
Typical 3-Point Accuracy
A curve is fitted to these points.
A detailed report including Raw
Temperature Data, Polynomial
Fits, and Interpolation Tables
comes with the sensor.
<10 K
12 mK
20 mK
10 K
12 mK
20 mK
20 K
15 mK
25 mK
30 K
25 mK
45 mK
50 K
30 mK
55 mK
100 K
25 mK
50 mK
300 K
25 mK
50 mK
340 K
100 mK
480 K
100 mK
Temp.
Typical
Maximum
- or -
C-331-2-1.eps
Figure 2-1. Silicon Diode Sensor Calibrations and CalCurve
2-4
Cooling System Design
