1 Brief description:
1.1 The sensitivity of the analytical balance is 0.1mg or 0.01mg, which is used for weighing in more precise inspection work, such as the determination of the content of drugs and the standardization of titration liquid.
1.2 Balances composed of the principle of levers are mechanical balances; balances that directly display mass readings based on the principle of electromagnetic force balance are electronic balances.
1.3 This regulation is applicable to the operation and use of mechanical balances and electronic balances.
2 balance room requirements:
2.1 The balance room should be close to the laboratory, easy to operate, should be far away from the vibration source, and prevent the interference of airflow and magnetic field.
2.2 Indoor requirements are dry and bright, the light is uniform and soft, and the sunlight must not be directly on the balance.
2.3 The ground of the balance room shall not be dusty, preferably terrazzo, and the walls and roof shall be flat and free of falling objects. The concrete structure of the sky platform is better. The table should be level and smooth. Generally, terrazzo is used, which is strong and shockproof, and has a suitable height and width. The temperature of the balance room should be relatively stable, generally controlled at 18-26 ℃, maintaining constant humidity, the relative humidity is 30% -65%, the room should be equipped with a temperature and humidity meter, generally using air conditioning to adjust the temperature and humidity. The balance room power supply requirements are relatively stable, and the voltage change should be small. Except for storing weighing-related items, no other items shall be stored in the balance room, and corrosive liquids and volatile solids shall not be transferred in the balance room.
3 Analytical balance usage:
3.1 Preparation before use:
3.1.1 Select the appropriate level according to the requirements of the amount of material weighed and the accuracy of weighing.
3.1.2 After selecting the balance, first check the balance's use registration record, check the balance's previous use and whether the balance is in a normal state.
3.1.3 If the balance is in a normal usable state, use a soft brush to lightly clean the dust on the balance plate, and open the glass doors on both sides of the balance for 3-5 minutes to make the temperature and humidity inside and outside the balance consistent, so as not to affect the stability of the balance.
3.1.4 Close the glass doors on both sides, open and close the balance so that the components of the balance are in the normal position. Before weighing, observe whether the balance is in a horizontal position, and then adjust the zero point.
3.2 Use of mechanical analytical balance:
3.2.1 Turn on the power first, close the doors on both sides of the balance, gently turn the switch handle to make the beam fall, and observe whether the normal or balance pointer on the light screen is in the "0" position.
3.2.2 If it is not far from "0", you can lightly adjust the zero point fine adjustment knob to make it coincide. If the normal or pointer is far from "0", you should turn off the switch, adjust the balance, and then turn on the balance.
3.2.1 Method adjustment Make the normal or pointer coincide with "0" and turn off the balance.
3.2.3 Place the weighed substance in the room in advance to keep it consistent with the temperature of the balance room. First weigh out the approximate weight of the weighing object with a tray balance, open the side door of the balance, and place the weighing object in the center of the tray. When putting the weighing object, you should wear gloves or pick it with a camera with a rubber sleeve. Take it by hand.
3.2.4 Place the weight in the center of the weight plate with a weight-specific camera. The mechanical weighting balance should gently turn the weight button to select the appropriate weight and add it to the weight riding beam.
3.2.5 Close the doors on both sides of the balance, gently turn the switch handle, and carefully observe the normal or pointer swing direction on the light screen. Generally, the right of the light screen indicates that the weight is too heavy. On the contrary, the weight is too light. The balance should be closed immediately. Add or subtract weights until they are in a balanced state (the normal of the light screen or the pointer is within the scale of the balance plate).
3.2.6 Read and record the weighing data according to the amount of weight added and the position of the normal or pointer of the light screen.
3.2.7 Turn off the balance, take out the weighed object and the weight and put it back to the original place according to the requirements at the time of putting in.
3.2.8 After use, it should be registered in the balance use record. The content of the registration shall include the date of use, the name of the object to be weighed, the number of weighings, the time of use, the status of the balance, the user, etc.
4 Weighing operation method:
4.1 Decrement method: put the test sample to be weighed into the weighing bottle, place it on the balance pan and weigh the reading to W1, then take out the weighed test sample, then put it on the weighing pan to record, reading For W2, W1-W2 is the weight of the test sample. Weighing by decrement method can continuously weigh several test samples, saving weighing time.
4.2 Incremental method:
4.2.1 Place the weighing bottle on the balance pan, weigh it as W1, add the test sample to be weighed into the weighing bottle, weigh as W2, and W2-W1 as the weight of the test sample.
4.2.2 It is necessary to accurately weigh the commonly used incremental method for the test sample.
5 matters needing attention:
5.1 Analytical balance should not be placed on the table under the air conditioner.
5.2 Balances that have been moved must be level-corrected and checked for measurement performance before use.
5.3 Turn the balance on or off slowly and carefully.
5.4 When weighing, try not to open the front door and top door, use the side door, and move gently when opening and closing the door.
5.5 The weights are only allowed to be picked up with a special camera, but not by hand. The weights can only be placed on the weight box or the balance plate, and are never allowed to be placed anywhere else. Each balance can only use its special weights. The weights cannot be used interchangeably.
5.6 When the balance (mechanical balance) is in the open state, you must never take items or weights on the weighing pan and open the balance door.
5.7 Weighing hygroscopic, volatile and corrosive drugs should be as fast as possible. Be careful not to spill the weighed objects on the balance pan or bottom plate. After weighing, the weighed objects should be taken away from the balance in time.
5.8 The same test should be weighed on the same balance to avoid errors.
Silicone Muffin Pan offers great advantages over the traditional metal pans. These Muffin Cake Mould are are lightweight and flexible. You never have to worry about them breaking, fading, getting scratched, dented or rusting.
The food bakes smoothly and brown beautifully. A silicone Muffin Baking Pan stops baking process once removed from the oven, unlike metal. It cools quickly, which makes it more convenient for using.
This Silicone Muffin Pan make it really simple to turn out or unmold your baked goods and cooked dishes. Because they are so flexible and non-stick, there is no more frustration with some of your beautiful creation getting stuck to the inside of the pan.
Muffin Pan,Muffin Cake Mould,Muffin Baking Pan,Cast Iron Muffin Pan
RealSheen Lifestyle Enterprise Limited , https://www.realsheen.com