What is the purpose of calibration in the context of weighing balance?

• To adjust the balance pan

• To clean the balance

• To replace instrument parts

• To compare the accuracy of measurements with known standards

What is the tolerance range in the context of weighing balance calibration?

• The permitted deviation between standard weight and scale reading

• The range of weights that can be measured

• The temperature range for calibration

• The time interval for calibration

What type of weights should be used for calibration of weighing balance?

• NIST Class A weights

• NIST Class S weights

• NIST Class C weights

• NIST Class B weights

What is the purpose of the Repeatability Test in the context of weighing balance verification?

• To determine the repeatability of the scale used

• To test for errors in weighing scale

• To test the sensitivity of the balance

• To determine the minimum weight change that the weighing device can detect

What does the Eccentricity Test determine in the context of weighing balance verification?

• The permitted deviation between standard weight and scale reading

• How the reading is affected when test load is placed at different locations of the weighing pan

• The minimum weight change that the weighing device can detect

• The repeatability of the scale used

What should be done before performing a test with a weighing balance to minimize errors?

• Place chemicals directly onto the pan

• Clean the balance pan with bare hands

• Drop objects onto the weighing pan

• Acclimatize the test weight to the ambient temperature of the balance

What is the purpose of keeping the sliding door of the chamber fully closed when using an analytical balance?

• To avoid air currents and minimize vibration or huge temperature difference inside vs. outside the housing chamber

• To increase air currents and minimize vibration

• To allow temperature difference inside vs. outside the housing chamber

• To avoid vibration and temperature difference inside vs. outside the housing chamber

What are some common reasons for erroneous readings in weighing balance? (More than one answer).

• Forgetting to keep chamber door closed to avoid air currents

• Sample not cooled sufficiently before placing into chamber

• Pan & floor chamber not free of chemical debris

• Bumping of balance or vibration that cause the internal parts to be faulty

What are the factors that can affect weighing accuracy?

• Magnetic field, dust and fumes, poor calibration and maintenance of equipment, air fluctuations

• Extreme temperature changes, unsuitable location, support, dust and fumes

• Vibration, air fluctuations, magnetic field, poor calibration and maintenance of equipment

• Support, extreme temperature changes, unsuitable location, vibration

What is the purpose of the balance level indicator in the context of weighing balance maintenance?

• To ensure that the air bubble is within the center circle of the level indicator

• To determine the minimum weight change that the weighing device can detect

• To measure the mass accurately

• To avoid air currents and minimize vibration