Final answer:
The frequency of checking the weight and pressure of factory-charged non-refillable containers depends on company policies, industry standards, and regulatory requirements. Without specific context, an accurate answer cannot be provided. The question does not relate directly to the scenario provided about the chemist checking the dispensing machines.
Step-by-step explanation:
The question does not provide enough context to accurately specify how many times a year the weight and pressure of factory-charged non-refillable containers are checked. Typically, this would depend on the regulations and protocols of the particular industry and company, as well as the specific type of container and its contents. If this question is related to the quality control checks performed by the chemist, as described in the reference information provided, the answer would be based on the protocols set by the company's quality control department. However, in the context provided, the question seems unrelated to the procedures described for the quality control chemist who is checking the accuracy and precision of machines dispensing cough syrup.
In the scenario presented, the chemist is concerned with verifying that machines are dispensing the correct volume of liquid into bottles. If we consider this process in relation to checking the weight and pressure of containers, this would likely be part of a broader quality control process, which can vary. It is not uncommon for critical equipment and controls to be verified multiple times throughout the year, but the exact frequency would be determined by company policy, industry standards, and any applicable legal or regulatory requirements.