How to do it in standard atmospheric humidity for 24 hours

Overview of the constant temperature and humidity laboratory protocol.

Constant temperature and humidity laboratory is to make a laboratory through some special equipment and technical methods to make its indoor temperature and humidity meet the requirements of a certain humidity control and test standard atmosphere. The constant temperature and humidity laboratory is the infrastructure for product quality inspection and control of production enterprises and commodity quality inspection in the field of circulation. Constant temperature and humidity laboratory is widely used in cotton spinning, wool spinning, chemical fiber, paper, packaging tobacco production enterprises and quality inspection, fiber inspection and other departments, in accordance with ISO and GB standards regulations, textiles, textile raw materials, paper products and cartons and other commodities of the quality of the physical items of the inspection must be carried out under standard atmospheric conditions.

The standard atmosphere for the inspection of textiles and textile raw materials is according to ISO139 and GB6529 standards, the temperature is 20 2, and the relative humidity is 65% 2%; The standard atmosphere for the inspection of paper, paper products and cartons is in accordance with the ISO187 and GB10739 standards, with a temperature of 23 1 and a relative humidity of 50% 2%. In addition to the conventional constant temperature and humidity laboratory, there are other special constant temperature and humidity laboratories with special requirements such as 5-18 low temperature, 30-80 high temperature, low humidity with relative humidity requirements of less than 40%RH and high humidity with relative humidity higher than 80%RH.

Constant temperature and humidity laboratory is to make a laboratory through some special equipment and technical methods to make its indoor temperature and humidity meet the requirements of a certain humidity control and test standard atmosphere. The constant temperature and humidity laboratory is the infrastructure for product quality inspection and control of production enterprises and commodity quality inspection in the field of circulation. Constant temperature and humidity laboratory is widely used in cotton spinning, wool spinning, chemical fiber, paper, packaging tobacco production enterprises and quality inspection, fiber inspection and other departments, in accordance with ISO and GB standards regulations, textiles, textile raw materials, paper products and cartons and other commodities of the quality of the physical items of the inspection must be carried out under standard atmospheric conditions.

The standard atmosphere for the inspection of textiles and textile raw materials is specified in ISO139 and GB6529 standards, with a temperature of 20 2 and a relative humidity of 65% 2%; The standard atmosphere for the inspection of paper, paper products and cartons is in accordance with ISO187 and GB10739 standards, with a temperature of 23 1 and a relative humidity of 50% 2%. In addition to the conventional constant temperature and humidity laboratory, there are other special constant temperature and humidity laboratories with special requirements such as 5-18 low temperature, 30-80 high temperature, low humidity with relative humidity requirements of less than 40%RH and high humidity with relative humidity higher than 80%RH.

Key points of constant temperature and humidity laboratory design.

The overall planning of the laboratory should take into account the following requirements: it involves a wide range of professionals such as architecture, water and electricity, air conditioning, and laboratory users.

Design purpose: to create one for laboratory equipment.

can ensure its stability and reliability.

operation, prolong its service life, and meet the requirements of users and the physical and mental health of staff.

This needs to be assisted by a untwisting machine.

Yarn twist: The number of twists of the yarn along the axial length to measure the degree of twisting of the same fineness yarn. The twist of the yarn obtained by the special number is expressed by the number of twists of 10 cm (twist 10cm), the yarn with the metric count of wool is expressed by the number of twists per meter (twist tn), and the cotton textile industry, foreign trade and other industries usually use the number of twists per inch of yarn to express the number of twists per inch of yarn, commonly known as inch twist (twist inch), silk and other industries also use the number of twists per centimeter of yarn (twist cm).

The determination of yarn twist usually uses a special twist tester, such as Y321 hand twist meter, Y331A or YG155 yarn twist meter, etc.

The twist tester should have a pair of clamps, one of which is a "rotary clamp", which can rotate forward and backward around the shaft and be connected to the counter. At least one clamp can be moved so that the length of the yarn to be measured can be varied in the range of 10 mm to 500 mm. There must be no gaps in the jaw openings.

There is a pre-tensioning device, which can measure the length of the specimen with an accuracy of ". The twist counting device records or displays the number of revolutions of the rotary clamp. If the specimen is to be tested for shrinkage or elongation, the movable clamp should not create significant friction when moving.

There are two methods for determining yarn twist:

Direct counting method, that is, under a certain tension, clamp the two ends of a length of yarn, and turn back in the direction of untwisting through one end of the sample to the other end until the fibers (or single yarns) in the yarn are completely parallel, and the number of twists withdrawn is the number of twists of the length of the sample.

Untwisting and twisting method, that is, under a certain tension, clamping the two ends of a length of yarn, after untwisting and reverse twisting, half of the number of twists required to return to the starting length is the number of yarn twists under the length. The textile industry has specified test methods for the selection of different types of yarns, and the length of the specimen should be as long as possible, but should be less than the average length of the staple fibers in the yarn.

Parameters such as the length of the sample commonly used should be selected according to the provisions of the textile industry standard or national standard.

The twist sample should be drawn according to the sampling regulations, and the humidity should be balanced in the standard atmosphere. According to the test results, the twist index can be calculated according to the following formula: average twist = (sum of twists of all specimens 1000) (specimen length mm number of tests).

Textiles Determination of yarn twist Part 1: Direct counting (GB t

Textiles Determination of yarn twist Part 2: Untwisting and twisting method (GB T

Cotton yarn (GB T 398-2008).

Air-spun cotton yarn (FZ T 12001-2006).

Inspection Rules for Cotton and Chemical Fiber Pure Spinning and Blended Natural Yarns (FZ T 10007-2008).

Inspection Rules for Cotton and Chemical Fiber Pure Spinning and Blended Natural Yarns (FZ T 10007-2008).

Cotton yarn ** specification (GB T 17033-1997).

If you need to buy a twist meter, if you want, you can send me a sample and I will test it for you. I'm also in Anhui.

GB T 14800-2010 Geosynthetics - Static Burst Test (CBR Method).

This standard specifies a method for determining the breaking strength of geosynthetics by means of a flat-end jacking rod. This method is usually carried out on a specimen after humidification of the specified standard atmosphere. This standard applies to all types of geosynthetics, but not to materials with pore sizes greater than 10 mm.

Refers to particulate matter in the atmosphere that is less than or equal to a micron in diameter, also known as particulate matter that can enter the lungs. Although only.

It is a very small component of the Earth's atmosphere, but it has important implications for air quality and visibility. The particle size is small, rich in a large number of toxic and harmful substances, and the residence time in the atmosphere is long, and the transportation distance is long, so it has a greater impact on human health and atmospheric environmental quality.

The World Health Organization (WHO) considers less than 10 to be a safe value, stating in its 2005 edition of its Air Quality Guidelines that the risk of death increases by about 15 per cent at an average concentration of 35 micrograms per cubic metre compared to 10 micrograms per cubic metre.

At present, China's standard is a 24-hour average concentration of less than 75 micrograms of cubic meters. Experts suggest that the average concentration of 24 hours is less than 35 micrograms cubic meters, and you can travel normally; Between 35 and 75, reduce outdoor activities; Over 75, try not to go out.

A new standard for air quality in the detection network.

According to the new air quality standard of the detection network, the distribution of the 24-hour average standard values is as follows:

Air quality rating 24-hour average standard value.

Excellent 50 Good 50 100

Lightly polluted 100 150

Moderate pollution 150 200

Heavy pollution 200 300

Severe pollution greater than 300 and above.

The 24-hour standard value in China is 75

Untie; According to the standard, 100-150 should be between light pollution and moderate pollution

Therefore, b