The lab electronic balance will produce measurement errors due to uneven placement during weighing. The higher the weighing accuracy, the larger the error (such as precision analytical balances and microbalances). For this reason, most electronic The balance provides the function of adjusting the level.
There is a level bubble behind the electronic balance. The level bubble must be in the center of the liquid cavity, otherwise the weighing will not be accurate. After adjustment, try not to move it, otherwise the level bubble may shift and need to be adjusted again.
Electronic balance generally has 2 leveling bases, generally located at the rear, but also located at the front. You can adjust the balance level by rotating these two leveling bases.
The following method is relatively simple.
1. Turn the left or right leveling base to adjust the level bubble to the center line of the liquid cavity first.
Rotating a left or right leveling base alone is actually adjusting the tilt of the balance, and you can definitely adjust the level to the center line.
The key is which leveling base. Beginners can judge this way by first tilting the balance manually so that the level bubble reaches the center line, and then see which leveling base is higher or lower. Adjust the height of one of the leveling bases to move the level bubble to the center line.
(Which side the level bubble is biased to, that side is low, it should be turned counterclockwise to raise the base)
Open (rise) and go through (decrease)
Note: the next step cannot be taken until the central line is reached
2. Rotate two leveling bases at the same time, the amplitude must be the same, both must be clockwise or counterclockwise to let the level bubble
Move in the center line, and finally move to the center of the liquid cavity
The level is soaked above, indicating that the top is low, and the base should be raised (inverted) at the same time;
If the leveling base is rotated clockwise or counterclockwise at the same time, the tilt of the balance does not change, so that the level bubble will not deviate from the center line, as long as there is no problem in the direction of rotation, it can certainly reach the center of the liquid cavity.
Rotate clockwise or counterclockwise at the same time: rotate both hands to level the base at the same time (one hand toward the chest and one hand outside the chest, the opposite direction, generally the base is rotated clockwise or counterclockwise at the same time)
Orientation problem: It is not easy for beginners to judge direction. You can manually raise the base or another support to move the bubble to the center, and then observe the level of the base to see if it needs to be adjusted up or down.
Note that in the second step, the amplitude of both hands must be the same. If they do not match, the beads will be offset from the center line. If it is offset, start over from step one.
After proficiency, you can usually level the level of an electronic balance in 1-2 minutes.
It's not glass beads, it's the bubble of the spirit level, the bubble is tilted to the side, and the corner screw on that side is raised until it is adjusted to the middle position of the bubble.
Lab Electronic Balance
We know that the newly purchased electronic analytical balances and waterproof electronic balances must be warmed up for more than half an hour before they can be used for weighing operations. Before the electronic balance is powered, we need to level the electronic analytical balance. By adjusting the two knobs on the back of the electronic analytical balance base for effective adjustment, when the horizontal bead is adjusted to the middle position of the circle center, it can be preheated by power on.