How equip electronic scales in pharmaceutical factories with calibration standard weights?

According to the new GMP requirements, prepare to equip production workshops and warehouses with bai standard weights for daily calibration. What preparations need to be done?

1. Statistics on the use of electronic scales: name, number, location of use, weighing range, accuracy requirements, calibration range.

2. How many standard weights should each scale be equipped with? Where are the regulations?

3. What are the requirements for the storage and management of standard weights?

4. How to formulate daily calibration procedures for electronic scales?

answer:

The grades of standard stainless steel weights for pharmaceutical weights are: E1, E2, F1, F2, M1, magnetic level; magnetic and non-magnetic.

Definition of pharmaceutical grade stainless steel weights:

Pharmaceutical stainless steel weights refer to the parts of food machinery such as stainless steel weights that contact food, and must meet certain food safety requirements. Because a lot of acid and alkali are used in the food production process, and stainless steel weights contain chromium, unqualified stainless steel weights will dissolve chromium at various prices during use, which is toxic; and it is required to limit lead, cadmium and other alloy impurity elements Content.

Generally, large-scale medical and pharmaceutical factories need to use precision weights as weighing instrument measurement and calibration balances, so what kind of weights are generally used, the following is a rough classification of pharmaceutical calibration weights:

One: JF-1 non-magnetic stainless steel weight with magnetic susceptibility ≤0.0006, material density 8.00g/cm3,

Two: 316 non-magnetic stainless steel weight magnetic susceptibility ≤ 0.01, material density 7.94g/cm3,

Three: 304 non-magnetic stainless steel weight magnetic susceptibility ≤ 0.05, material density 7.85g/cm3.

It is recommended that the higher the accuracy of pharmaceutical weights, the better. This is also a guarantee for the users

In recent years, foreign countries have used digital systems to achieve weightless calibration for non-mandatory weighing instruments, that is, weighing instruments used in production. Another method is to use the display to have the function of amplifying the weighing display value during calibration. For example, a fieldbus converter has this function. The number of calibration weights. These two methods are very effective for some well-designed weighing instruments, such as bucket scales, tank scales, and a large number of process scales used in steel and metallurgical industries.

Weighing instrument is a widely used measuring instrument in people's lives. People use it to measure the weight or mass of objects. In physics, mass, length and time are the three basic physical quantities. The concept of "mass" is a "physical quantity" introduced by Newton as classical mechanics around 1700 to describe the "inertia" of objects in motion, and our sense organs cannot directly perceive quality. But as early as two to three millennia BC, people understood the principle of lever balance, that is, using a simple equal-arm balance to measure the weight or mass of an object. All kinds of weighing instruments nowadays are also measuring instruments for measuring the mass of objects. The weight is the standard instrument of mass measurement, and the standard mass of the agreed kilogram reference weight is transferred to various weighing instruments to unify the value of the mass.

Most types of weighing instruments can be calibrated with weights. For weighing instruments that cannot be directly calibrated with weights, such as automatic weighing instruments such as belt scales, indirect methods are also required to make the calibration value traceable to the kilogram reference weight. It is the basic element of weighing instrument calibration that the weighing value of the calibrated instrument can be traced to the kilogram reference weight. Another basic element of weighing instrument calibration is that the calibration methods and procedures should be as consistent as possible with the actual weighing process of the weighing instrument. That is to meet the principle of "accurate, consistent and correct use" of our measurement. As for the influence factors and interference factors such as temperature and humidity, they are determined according to the environmental conditions of the weighing instrument.

For the verification of large weighing instruments, several tons to dozens of tons of weights are required. This does not meet the requirements of the legal verification amount for both the user and the basic measurement department. On the other hand, it is laborious, time-consuming, and expensive for users to send these weights to the measurement department on a regular basis. This is a common problem. The use of a weight comparator (high-precision large-range scale) to verify large weights by comparing with high-precision weights has been recognized by everyone, so qualified users can use this method to verify the weights used, or even by themselves If you purchase the device for self-verification, you only need to send the device to the metrology department for verification on a regular basis. 】