Sensor Calibrations And Precision Options - Lakeshore 330 User Manual

Lake Shore Model 330 Autotuning Temperature Controller User's Manual
With regards to accuracy, there
are 3 things that can be done
with a temperature sensor:
Standard
Standard sensors are
interchangeable within the
published tolerance band.
Standard Curv e 10 Tolerance
(Accuracy ) Bands f or DT-470
are listed below.
2 K* - 100 K -
Band
100 K 305 K
11 ±0.25 K ±0.5 K
11A ±0.25 K ±1% of Temp.
12 ±0.5 K ±1.0 K
12A ±0.5 K ±1% of Temp.
13 ±1 K ±1% of Temp.
* Temperatures down to 1.4 K only
with a Precision Calibrated Sensor.
To increase accuracy , the
User may perf orm a
Sof tCal™ with his controller
and sensor. Once a sensor is
calibrated, the standard
Curv e 10 is replaced with the
custom curv e f or that
sensor.
A Precision Option can be
generated for either SoftCal™
or the Precision Calibration:
Precision Option
breakpoint pairs
are loaded in a
NOVRAM and
f actory
installed.
Operation
Lake Shore DT-400 Series
Silicon Diode Temperature Sensor
SoftCal™
Calibration
A Lake Shore Sof tCal™ can only be
perf ormed on Silicon Diodes. For a
2 point Sof tCal™, data points are
taken at 77.35 K and 305 K. For a 3
point Sof tCal™, data points are
taken at 4.2 K, 77.35 K, and 305 K.
305 K -
Typical 2 Point Accuracy
375 K
±1.0 K
±1.0 K
±0.25 K
±0.15 K
±2.0 K
±0.25 K
±1.0 K
Typical 3 Point Accuracy
±0.5 K
±0.25 K
±0.15 K
±0.25 K
±1.0 K
A v oltage is taken at the 2 or 3
data points. These v oltages can be
entered into controllers with
Sof tCal™ capability . A calibration
report is sent with the sensor.
Precision
Option
8001
8000
Precision Option
breakpoint pairs
are loaded on a
Floppy Disk in
ACSII f ormat f or
Customer
downloading.
Figure 3-3. Sensor Calibrations and Precision Options
2 K to <30 K
30 K to <60 K
60 K to <345 K
345 K to <375 K
375 K to 475 K
2 K to <30 K
30 K to <60 K
60 K to <345 K
345 K to <375 K
375 K to 475 K
- or -
8002-05
Precision Option
breakpoint pairs
are loaded in a
NOVRAM f or f ield
installation.
Precision
Calibration
Lake Shore can do a precision
calibration on most sensor ty pes. Up
to 99 separate data points can be
taken, with the ability to concentrate
taking data in areas of particular
interest. Ty pical calibration accuracy
f or silicon diodes is listed below.
Typical Precision Cal. Accuracy
Temp. Typical Maximum
<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
A curv e is f itted to these points. A
v ery detailed report that includes:
• Raw Temperature Data
• Poly nomial Fits
• Interpolation Tables
is sent with the sensor.
User calculates break-
points and manually enters
data into the controller
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