What type of balance do pharmacies use?
The National Bureau of Standards (NBS) requires pharmacies to have a “Class A” Prescription Balance on-site. This balance uses internal and external weights and has two-pans; it is a torsion-type balance.
What is balance sensitivity?
Sensitivity of a balance. A balance is said to be sensitive when it can register small differences in weight. The balance beam is most sensitive when its center of gravity lies slightly below its rotation axis.
How do you calculate LWQ?
To calculate the amount of drug to weigh out, multiply the amount of drug ordered by a whole number until you have an amount equal to or greater than the LWQ. This number is called a factor and it can be any number you want. Just remember we want to keep it as close to the LWQ as possible.
What does the tare button do on a scale?
All Escali digital kitchen scales come with a Tare Feature. Pressing the Tare button (which is sometimes labeled 'Zero') will reset the displayed weight on the scale back to zero. The Tare button can also be used to measure multiple items in the same container.
What is an example of a two pan balance?
A double-pan balance can also be used to determine how much of a substance makes up a specified weight. For example, if you wanted to measure 10 grams of sand, you could load 1 pan with a 10-gram weight, and then place sand in the other pan until it balances.
What type of balance is a Class 3 prescription balance and a counterbalance?
A Class III balance (formerly known as a class A prescription balance) is a two pan balance that can weigh 120g or less with a sensitivity requirement (SR) of 6mg.
What is the sensitivity of the balance?
Sensitivity of a balance is one of the most important specifications. The sensitivity (S) is given by the change in the weighing value ΔW divided by the load variation Δm (Equation 1). The balance sensitivity can be described by the slope of a calibration line measured over a nominal range (Figure 1).
Why is it important to use correct weighing and measuring equipment in pharmacy?
Performing quality risk management helps avoid the risk of weighing incorrectly. Have a complete understanding of the devices that are being used for weighing in the facility, and gather information on the measurement possibilities that need to be controlled and used in practice.
What are the common solvents used in preparing solutions?
Solvents. Water (H2O) is the most common solvent, used for dissolving many compounds or brewing coffee. Other common solvents include turpentine (a paint thinner), acetone (nail polish remover), and ethanol (used in some perfumes). Such solvents usually contain carbon and are called organic solvents.
What is the sensitivity requirement of a Class A torsion balance?
The sensitivity requirement or limit of a Class A balance is defined as a pointer shift of not less than one index-scale division when 6 mg has been added to a pan.
Which type of mortar and pestle is used to mix liquids?
The mortar is a bowl and the pestle is a small club-shaped tool. They are typically made from ceramic or stone. Pipette – A narrow glass tube used to transfer liquids from one place to another.
Which balance has a sensitivity requirement of +/- 6 mg?
The Class III Balance has a sensitivity requirement of 6 mg, meaning that as much as 6 mg could be added to or removed from the pan before the balance marker will move 1 division. Most have a maximum capacity of 120 g and bear a statement to that effect.