Standard Methods; 2550 A, 2550 B
The temperature test is a measurement of hotness or coldness. Temperature is one of the most common measurements used in the laboratory. The Centigrade system is commonly used in the laboratory, however, Fahrenheit can also be used. Another scale that may be referenced is the Kelvin scale. This is rarely used outside of scientific settings. To convert from Centigrade to Kelvin, add 273° to the Centigrade temperature.
|
Total immersion |
A total immersion thermometer must be totally immersed when read. |
|
Partial immersion |
A partial immersion thermometer will have a solid line around the stem at the immersion point. |
|
Liquid filled |
These are filled with mercury, spirits (alcohol), or biodegradable liquids and can be obtained in a variety of accuracy levels depending on need. Note that mercury is a hazardous material. If a mercury-filled thermometer is broken, cleanup, transportation, and disposal of the waste must be done in accordance with local, state, and federal guidelines. The biodegradable liquid and spirit-filled thermometers can be easily disposed of if broken and are of equal quality and accuracy as the mercury-filled thermometers.. |
|
Dial |
These are constructed of corrosion-resistant metal or plastic and are a durable alternative to glass thermometers. A probe is inserted into the material being measured and the temperature is read on the dial on top of the probe. |
|
Digital |
These are constructed of a probe, a thermocouple, and a processor (meter or alarm). Some of the meters will also store data points or feed the data to a computer as they are gathered. |
|
Infrared |
These electronic thermometers can determine temperatures without coming into contact with the material of interest. They collect energy that has been transmitted, reflected, or emitted from an object and focus it onto a detector which converts the energy to a specific temperature. At close range they can measure the temperature of an area less than a square inch. These are well suited to measure temperatures of moving objects, hard to reach objects, or hazardous materials. |
It is not possible to store or preserve a sample that needs to have the temperature analyzed. The temperature of the sample must be taken immediately after sampling. A large volume should be collected. The use of a large volume is to prevent ambient or surrounding air temperatures from changing the temperature of the sample.
Check your thermometer accuracy by measuring a sample with both thermometers. (Your thermometer and the NIST thermometer should be immersed simultaneously into the same sample). Be sure to note whether the thermometer is a total or partial immersion type and immerse it appropriately.
Converting ° F to ° C
Example; Convert 77° F to ° C
Converting °C to °F
Example; Convert 50°C to °F
|
° C |
° F |
|
° C |
° F |
|
- 10 |
14.0 |
|
15 |
59.0 |
|
- 9 |
15.8 |
|
16 |
60.8 |
|
- 8 |
17.6 |
|
17 |
62.6 |
|
- 7 |
19.4 |
|
18 |
64.4 |
|
- 6 |
21.2 |
|
19 |
66.2 |
|
- 5 |
23.0 |
|
20 |
68.0 |
|
- 4 |
24.8 |
|
21 |
69.8 |
|
- 3 |
26.6 |
|
22 |
71.6 |
|
- 2 |
28.4 |
|
23 |
73.4 |
|
- 1 |
30.2 |
|
24 |
75.2 |
|
0 |
32.0 |
|
25 |
77.0 |
|
1 |
33.8 |
|
26 |
78.8 |
|
2 |
35.6 |
|
27 |
80.6 |
|
3 |
37.4 |
|
28 |
82.4 |
|
4 |
39.2 |
|
29 |
84.2 |
|
5 |
41.0 |
|
30 |
86.0 |
|
6 |
42.8 |
|
31 |
87.8 |
|
7 |
44.6 |
|
32 |
89.6 |
|
8 |
46.4 |
|
33 |
91.4 |
|
9 |
48.2 |
|
34 |
93.2 |
|
10 |
50.0 |
|
35 |
95.0 |
|
11 |
51.8 |
|
36 |
96.8 |
|
12 |
53.6 |
|
37 |
98.6 |
|
13 |
55.4 |
|
38 |
100.4 |
|
14 |
57.2 |
|
|
|
Goals for a New Analyst Performing Temperature Analyses
Temperature Analysis; the Tips for Techs version