Download Table 1. Maximum acid exposure time. - CMA

TEMPERATURE SENSOR 0511
-20 .. 125 °C
USER’S GUIDE
Figure 1 The Temperature Sensor 0511
CENTRE FOR MICROCOMPUTER APPLICATIONS
http://www.cma-science.nl
Description
The Temperature sensor 0511 measures temperature and temperature differences in
the range of -20C to 125C. This sensor uses the 20 k NTC thermistor (thermal
resistor), which is positioned in a stainless steel tube. The thermistor is a variable
resistor whose resistance decreases nonlinearly with increasing temperature. The
best-fit approximation of this non-linear characteristic is the so-called Steinhart-Hart
equation.
A lab interface measures the resistance value, R, at a particular temperature, and
converts the resistance using the Steinhart-Hart equation:
T = [K0 + K1(ln 1000R) + K2(ln 1000R)3]-1 - 273.15
where T the temperature in C, and R the measured resistance in k
K0 = 1.02119 x 10-3, K1 = 2.22468 x 10-4 and K2 = 1.33342 x 10-7.
The sensor has a built-in facility for automatic sensor identification (Auto-id sensor).
Examples of experiments
The temperature sensor is a general-purpose laboratory sensor. It is designed to be
used as you would use thermometer for experiments in chemistry, physics, and
biology. Examples of applications are:
- Measuring freezing and boiling points.
- Monitoring endothermic and exothermic reactions.
- Specific heat experiments.
Sensor Chemical Tolerance
The temperature sensor body is constructed from grade 316 stainless steel. This
high-grade stainless steel provides a high level of corrosion resistance for use in the
science classroom. Here are some general guidelines for usage:
1. The probe handle is constructed of molded plasticized Santoprene™ . While this
material is very chemical resistant, we recommend that you avoid submerging
the probe beyond the stainless steel portion.
2. Always wash the probe thoroughly after use.
3. The probe can be left continuously in water at temperatures within the range of –
25° to 150°C. Continuous usage in saltwater will cause only minor discoloration
of the probe, with no negative effect on performance.
4. You can leave the probe continuously in most organic compounds, such as
methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, n-hexane, lauric acid,
paradichlorobenzene, phenyl salicylate, and benzoic acid. The probe should not
be left in n-pentane for more than 1 hour.
5. The probe can be left in strong basic solutions, such as NaOH, for times up to 48
hours, with only minor discoloration. We do not recommend usage in basic
solutions that are greater than 3 M in concentration.
6. The Table 1 provides the maximum length of time we recommend for probe
exposure to some common acids. Probes left in an acid longer than these times
may bubble and/or discolor, but will still be functional. We do not recommend
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probes be left to soak in any acid longer than 48 hours.
Acid
1 M HCL
2 M HCL
3 M HCL
1 M H2SO42 M
H2SO4
3 M H2SO4
1 M HNO3
2 M HNO3
3 M HNO3
1 M CH3COOH
2 M CH3COOH
3 M CH3COOH
1 M H3PO4
2 M H3PO4
3 M H3PO4
Maximum
Exposure Time
20 minutes
10 minutes
5 minutes
48 hours
20 minutes
10 minutes
48 hours
48 hours
48 hours
48 hours
48 hours
48 hours
48 hours
48 hours
48 hours
Table 1. Maximum acid exposure time.
Calibration
The output of the temperature sensor is
non-linear with respect to temperature.
Simple use the calibration supplied in the
standard sensor library of the Coach
program.
The name of the Temperature sensor in the
standard sensor library of the Coach
program is Temperature sensor (0511bt)
(CMA) (-25..150°C).
Figure 2.
Default calibration graph of the
Temperature sensor used in the standard
Coach sensor library.
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Technical data
Temperature range
-20 C to 125 C
Principle, calibration type
20 k NTC Thermistor; non-linear
Calibration curve
(Steinhart-Hart equation)
T = [K0 + K1(ln 1000R) + K2(ln 1000R)3]-1
Where T the temperature in C, and R the measured
resistance in k
K0 = 1.02119E-03; K1 = 2.22468E-04; K2 = 1.33342E-07
Coefficients
Maximum temperature that
sensor can tolerate without
damage
150 C
Resolution using 12 bit 5 V
A/D converter
0.08 C (-25 to 0C)
0.03 C (0 to 40C)
0.1 C (40 to 100C)
0.25 C (100 to 125C)
Accuracy
 0.2 C at 0 C and  0.5 C at 100 C
Maximum current drain
0.5 mA
Response time
95% of full reading: 11 s
98% of full reading: 18 s
100% of full reading: 30 s
Probe dimensions
Probe length (handle plus body): 16 cm
Stainless steel body: length 11 cm, diameter 4 mm
Probe handle: length 5 cm, diameter 1.25 cm
Connection
Right-hand BT (British Telecom) connector
Warranty:
The 0511 Temperature sensor is warranted to be free from defects in materials and
workmanship for a period of 12 months from the date of purchase provided that it
has been used under normal laboratory conditions. This warranty does not apply if
the sensor has been damaged by accident or misuse.
Note: This product is to be used for educational purposes only. It is not appropriate
for industrial, medical, research, or commercial applications.
Rev. 11/5/12
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