Content1. What is cryoscope?
1.1 What is the freezing point in the cryoscope for milk?
1.2 Working principle of cryoscope
1.3 Feature of cryoscope
1.4 Technical parameter of cryoscope2. How does cryoscope help determine if milk is watered down?
2.1 Cryoscope for milk
2.1.1 Principle of milk freezing point determination
2.1.2 How to determine the amount of milk watering?3. Use of cryoscope
4. How to buy cryoscope?
What is cryoscope?
is a new digital display instrument for fast and precise measurement of the freezing point temperature of milk samples, using crystallization temperature measurement for supercooled solutions. The parameters of this instrument are in accordance with the relevant European standards for raw milk, liquid milk, etc. (e.g. skim milk, pasteurized milk, and UHT), where the freezing point temperature of the milk is directly affected when water is added to the milk.
Since milk has various components such as fat and protein dissolved in it, the freezing point of milk is lower than that of water. The freezing point of normal milk is -0.52~0.53℃ on average, while the freezing point of water is 0℃, if water is added to milk, the freezing point of the whole sample will rise. Under normal circumstances of 1% water admixture, the freezing point of the mixed sample rises about 0.0053, when 100% water admixture, the temperature rises to 0.530 ℃, at which time the instrument shows the freezing point temperature of 0 ℃, showing that water admixture is 100%.
Cryoscope is a laboratory instrument that uses a temperature probe to measure the temperature of the freezing point of the mixed sample and a formula inside the instrument to calculate the percentage of water mixed in the milk sample.
What is the freezing point in the cryoscope for milk?
is the point at which a certain non-solid substance becomes solid under certain pressure and other conditions called the freezing point or solidification point.
In other words, fresh water freezes at 0°C, which is called the freezing point. The freezing point of raw cow's milk is an uncertain temperature. Because, raw milk contains a large number of inorganic salts, protein, and fat. Therefore, the freezing point of cow's milk varies closely with the composition and density of cow's milk.
Working principle of cryoscope
The flow of cooling liquid causes the buttermilk temperature to drop while stirring the buttermilk so that the surface layer of buttermilk loses heat and the buttermilk is cooled. Buttermilk temperature drops, when the temperature of buttermilk is close to the temperature when the density of buttermilk is at its maximum, the specific gravity of the surface layer of buttermilk is medium to large, and the specific gravity of the inner layer of buttermilk becomes relatively small, then convection mixing occurs between the surface layer and inner layer of buttermilk. The cooling process brings the cooled buttermilk from the surface layer to the inner layer, and then the crystalline tropics released during the formation of ice crystals in the inner layer are brought to the surface, and the buttermilk is cooled again until the density of the whole buttermilk is uniform and stable before it stops. The milk begins to freeze when the milk temperature drops to the freezing point and continues to dissipate heat.
Feature of cryoscope
a. Good flexibility and adaptability. Fixed time mode and scanning mode for freezing point testing can be selected. All necessary parameters can be pre-programmed and stored, suitable for each country's standards.
b. User-friendly interface. Built-in German, English, French, Greek, Italian and Spanish menus are available.
c. Excellent performance. Newly designed cooling system, fast cooling speed, little interference from ambient temperature to the instrument.
d. Universality. Standard computer output interface (RS232 and LPT), standard with software included, can be connected to 12V DC working, outdoor working can be connected to a car battery or other solar battery for power supply.
e. Easy to use. The instrument is small in size and light in weight, easy to transport and operate. Test results (water admixture) are automatically displayed and printed out. Automatic calibration, all set parameters, and calibration values can be recorded in the fixed repository.
Cryoscope using imported dual compressor refrigeration, fast cooling, simple structure, beautiful appearance, automatic detection, automatic results; unique custom standard freezing point test instrument, the application of microprocessor technology, the use of microcomputer operation and control, humanized temperature curve can be a real-time observation of specimen changes, automatic storage and final results print test results. Instrument-integrated large-capacity storage devices can store experimental data.
Technical parameter of cryoscope
|Power supply||AC220V±10％ 50Hz
|Power supply power||2000W
|Two-hole bath||Two specimens can be done at the same time
|Bath temperature range||Room temperature ~ -75 ℃ within any setting
|Temperature control accuracy||±0.1℃
How does cryoscope help determine if milk is watered down?
The freezing point of raw milk is generally between -0.525℃ and -0.535℃. If the milk is mixed with water, the freezing point of the diluted milk will rise, and the more water is mixed, the higher the freezing point. Generally, for every 1% of water added, the freezing point can rise by 0.0054℃. Therefore, monitoring the freezing point fluctuation is one of the effective means to control the moisture content in the milk production and processing process.
Europe and the United States use the method of freezing point testing to monitor the quality of raw milk, for example, Germany's milk quality regulations require that the freezing point of milk produced by producers be checked frequently, and must ensure that at least once a month if the freezing point is higher than -0.520 ℃ may indicate that the milk is adulterated with water.
Cryoscope for milk
Principle of milk freezing point determination
The milk is rapidly cooled down to -5~-8℃, when the milk is still liquid, the vibration of the stirring wire induces icing, which will cause the temperature to rise to a supreme point and remain constant for a short time, the constant temperature is the freezing point of the milk.
(The blue line represents pure water, the red line is milk, △T is the measured freezing point value of milk)
How to determine the amount of milk watering?
When milk is mixed with water, the amount of milk mixed with water can be calculated based on the change in freezing point, which is calculated as follows.
W(%) = 100 - [(Ti/T0)*100]
W(%): the amount of water adulteration;
Ti: the value of freezing point after water adulteration;
T0: the actual value of milk freezing point.
|Raw milk||Raw milk (watered down)
|Test 1||-0.527 ℃||-0.476 ℃
|Test 2||-0.527 ℃||-0.478 ℃
|Test 3||-0.527 ℃||-0.478 ℃
|Test 4||-0.528 ℃||-0.476 ℃
|Test 5||-0.530 ℃||-0.475 ℃
|Test 6||-0.527 ℃||-0.476 ℃
|Average value||-0.528 ℃||-0.476 ℃
Using the above table as an example, the average value of freezing point for six measurements of fresh milk is -0.528°C and the average value for six measurements after water mixing is -0.476°C.
The actual freezing point of the milk is T0 = -0.528°C, and the freezing point of the milk is Ti = -0.476°C after mixing with water.
W(%) = 100 - [(-0.476/-0.528)*100] = 9.85
This figure represents 9.85 grams of water per 100 grams of milk.
Use of cryoscope
a. The refractive prism will be aligned with the light direction, adjust the eyepiece sight ring, until the marker is clear.
b. Adjust the reference. Before measurement, first use the standard solution (pure water), the instrument and the liquid to be measured based on the same temperature. Lift the cover plate, then take 2~3 drops of standard solution on the refractive prism and gently press the flat cover plate by hand to see a blue-white demarcation line through the eyepiece. Rotate the calibration peg to make the blue-white line in the eyepiece field of view coincide with the reference line (0%).
c. Measurement. Wipe the prism surface and cover it with soft flannel, lift the cover, take 2~3 drops of the measured solution on the refractive prism, cover the cover and gently press the flat, do not have air bubbles inside, then read the relative scale of the blue-white demarcation line through the eyepiece, which is the measured value of the measured liquid.
d. After the measurement, wipe clean the prism surface and the attachment on the cover plate directly with a damp flannel cloth, leave it to dry, and store it properly.
e. When measuring the battery fluid, take care not to spill it on the skin and eyes to prevent burns, and wipe the instrument carefully after the test.
How to buy cryoscope?
ANTITECK provide lab equipment, lab consumable, manufacturing equipment in life sciences sector.
If you are interested in our cryoscope or have any questions, please write an e-mail to firstname.lastname@example.org, we will reply to you as soon as possible.