Module 7 - Weights and Measures

What are the 2 primary measurement systems healthcare workers use?

1. Household System (U.S. Customary Units): Commonly used in daily life (e.g., inches, pounds, teaspoons).

2. Metric System (International System):

What are the 3 common measurement units?

1. Weight: Ounce (oz), Pound (lb), Gram (g), Kilogram (kg)

2. Length: Inch (in), Foot (ft), Yard (yd), Millimeter (mm), Centimeter (cm), Meter (m)

3. Volume: Teaspoon (tsp), Tablespoon (Tbsp), Fluid Ounce (fl oz), Cup, Pint (pt), Quart (qt), Gallon (gal), Milliliter (ml), Liter (L)

What are the 4 common equipment to measure weight?

1. Standing scale – Used for ambulatory patients.

2. Wheelchair scale – Measures weight while the patient is in a wheelchair.

3. Bed scale – Used for patients who are bedridden.

4. Mechanical lift with scale – Weighs immobile patients who cannot stand or sit up.

What are the 2 common equipment to measure height/length?

1. Measuring tape – Used for patients who cannot stand, such as bedridden individuals.

2. Height rod (attached to scale) – Measures standing height.

What are the 3 common equipment to measure volume?

1. Graduated cylinder – Measures fluid intake/output with precise accuracy.

2. Measuring cups and spoons – Used for liquid medications.

3. Urinal and catheter drainage bag – Used for measuring urine output in patients.

What are the 2 common conversion for weight?

1 kg = 2.2 lb

AND

1 lb = 16 oz

What are the 2 common conversions for length?

1 inch = 2.5 cm

AND

1 foot = 12 inches = 30 cm

What are the 6 common conversion for volume?

• 1 oz = 30 ml

• 1 cup = 240 ml = 8 oz

• 1 pint = 500 ml

• 1 quart = 1000 ml = 1 L

• 1 tsp = 5 ml

• 1 Tbsp = 15 ml

What are the 5 steps to weighing a patient on a scale?

1. Ensure the scale is balanced at zero.

2. Have the patient remove shoes and heavy clothing to get an accurate reading.

3. Assist the patient onto the scale, ensuring they stand still and upright.

4. Read the weight at eye level to avoid misreading the measurement.

5. Record the weight accurately in pounds or kilograms, depending on facility requirements.

What are the 3 steps to measuring height on an upright scale?

1. Ensure the patient stands straight with feet flat on the floor.

2. Lower the height measurement rod gently onto the patient’s head.

3. Read and record the height in feet/inches or centimeters, depending on standard practice.

What are the 4 steps to measuring volume on a graduated cylinder?

1. Pour the liquid into the graduated cylinder carefully.

2. Place the cylinder on a flat surface to ensure accuracy.

3. Read at eye level from the bottom of the meniscus (curved surface of the liquid).

4. Record the measurement in milliliters (ml).

What are the 7 general guidelines to accurately measure a patient?

1. Always ensure measuring devices are calibrated correctly before use.

2. Weigh patients at the same time of day using the same scale for consistency.

3. Ensure patients urinate before weighing to avoid fluctuations in weight measurements.

4. Use proper body mechanics when assisting patients onto scales to prevent injuries.

5. Record measurements immediately in the patient’s medical chart to avoid forgetting.

6. Report sudden weight loss or gain to a nurse or physician as it may indicate underlying health issues.

7. Double-check conversions before documenting measurements to avoid errors.

Calibration

Adjusting and checking medical instruments to ensure accuracy in measurements.

Conversion Factor

A number used to change one unit of measurement to another.

Fluid Intake and Output (I&O)

The amount of fluids a patient consumes and excretes within a specific period.

Graduated Cylinder

A measuring tool used for precise liquid volume measurements.

Household Measurement System

A system using common units like teaspoons, cups, and ounces.

Kilogram (kg)

A unit of mass in the metric system; 1 kg = 2.2 lbs.

Liter (L)

A unit of liquid volume in the metric system; 1 L = 1000 ml.

Meniscus

The curve seen at the surface of a liquid in a graduated cylinder; read from the lowest point for accuracy.

Metric System

The international decimal-based measurement system used in healthcare.

Military Time

A 24-hour clock system used in healthcare to avoid confusion between AM and PM.

Ounce (oz)

A unit of weight or volume; 1 fluid oz = 30 ml.

Pound (lb)

A unit of weight in the household system; 1 lb = 16 oz.

Precision

The degree of accuracy in taking and recording measurements.

Standardized Measurement

A system that ensures consistency in medical records and

patient care.

Standing Scale

A tool used to weigh ambulatory patients.

Tare Weight

The weight of an object (such as a wheelchair or bed) that must be subtracted to obtain the patient’s true weight.

Urinal/Catheter Bag Measurement

A method used to measure urine output in milliliters (ml).

Volume Measurement

The process of determining the amount of liquid in ml or liters.

Weighing Consistency

The practice of taking weight measurements at the same time of day for accuracy.

Zeroing a Scale

Setting the scale to zero before weighing a patient to ensure an accurate reading.