Types of thermometers
With the development of science and technology and the needs of modern industrial technology, temperature measurement technology is also constantly improving and improving. As the temperature range is more and more widely, according to different requirements, but also create different needs of the temperature measurement equipment. Here are a few. Introduction
Digital thermometer is the use of temperature sensors (temperature) into digital signals, and then through the display (such as LCD, LED, LED matrix, etc.) to display the digital form of temperature, can quickly and accurately measure the maximum temperature of the human body, with the traditional Mercury thermometer, compared with reading a number of convenient, short measurement time, high accuracy, can remember and have the advantages of sound, especially digital thermometer does not contain mercury, harmless to humans and the surrounding environment is particularly suitable for hospitals, home use.
1 . Before using the thermometer, the head of the thermometer should be sterilized with alcohol.
2 . Press the switch, the buzzer immediately beep, the display shown in Figure A, the time is about 2 seconds.
3. Then the display shows the temperature of the last side of the volume as shown in Figure B (if the last measurement of 36.5 ℃), wells for 2 seconds or so. The display may then appear as shown in the C image. "℃" symbol flashes, indicating that the thermometer has been in the side of the state. (If the room temperature is higher than 32 ° C, the thermometer will display room temperature without displaying it as shown in figure D, while the "°" symbol is flashing).
4. Use a thermometer to measure body temperature. The amount of temperature showed a gradual increase in the temperature value, while "℃" symbol constantly flashing.
5. When the temperature rise speed in 16 seconds is less than 0.1 ℃, "℃" symbol stops flashing, while the thermometer beeps about 5 seconds, when the thermometer is completed, you can read the displayed temperature value. Spilled mercury must be collected immediately with a dropper, brush, and covered with water (preferably glycerin), and then sprinkle with sulfur powder at the contaminated area, without liquid (generally about a week) before cleaning.
The thermometer readings are not evaluated. Or that the last digit of the readout is the exact value, no need to re-evaluate the number behind the index value.
The use of mercury thermometers
When using a thermometer, first see its range (measuring range), and then see its minimum scale value, that is, the value of each small box. To select the appropriate thermometer to measure the temperature of the measured object. When measuring, the bubble of the thermometer should be in full contact with the measured object, and the glass bulb can not touch the sidewall or bottom of the measured object; when reading, the thermometer should not leave the measured object, and the line of sight of the eye should be with the liquid surface in the thermometer level.
1. Calibration should be carried out before use (can be used to compare the standard temperature of the multi-comparison method to verify or use more accurate thermometer calibration).
2. It is not permissible to use a measurement that exceeds the maximum scale value of the thermometer.
3. The thermometer has a thermal inertia and should be read after the thermometer reaches a steady state. Reading should be in the temperature convex meniscus maximum tangent direction of reading, eyes look.
4. Must not be used as a stir bar.
5. Mercury thermometer should be measured with the direction of flow is vertical or inclined.
6. Mercury thermometer mercury column fracture often occurs, to eliminate the methods are:
① cold repair method: the temperature of the thermometer into the dry ice and alcohol mixture (the temperature shall not exceed -38 ℃) for cold shrink, so that all the mercury in the capillary shrink to the temperature of the package so far.
② hot repair method: the thermometer slowly inserted temperature is slightly higher than the upper limit of the thermostat bath, so that part of the mercury fracture with the mercury column connected, and then slowly remove the thermometer, gradually cooled to room temperature in the air.