Weight to Calibrate

Selecting Equipment to Measure Weight in Infants
A pan-type pediatric scale allows a baby to be weighed while lying down. These types of scales are either electronic or beam scales with non-detachable weights, and are accurate to the nearest 10 grams. Another option is the hanging scale. A hanging scale needs to be attached to a sturdy structure (e.g. building rafter, door frame) and the child is suspended from the scale in weighing pants. It is important when using this equipment that the child remain calm and not become agitated to ensure accurate results. A third option is to use a digital scale. For this equipment option, the mother/caregiver/practitioner needs to step on the scale and the scale needs to be tared (set to 0) and then the infant handed to the individual. Once the scale is tared, the weight displayed is the weight of the infant. Please also watch the video below.

Selecting Equipment to Measure Weight in Children
Children’s weight should be measured using a flat digital scale that can measure to the nearest 100 grams (approximately ¼ pound). An ideal scale has multiple pressure transducers under the weighing platform, so they are less sensitive to variation in the child’s position and shifting of weight from one leg to the other. These scales are generally portable and operated by battery. The scale should have a taring function and be able to measure in both kilograms and pounds.

Equipment Setup
Both the infant and the digital standing scale should be placed on a flat, hard, and even surface. An infant scale can be placed on a table while the standing scale should be placed on the floor. Standing scales should not be placed on a loose carpet or rug. In certain situations, a wooden board may be placed on top of a soft surface to create a flat, hard, and even surface for a standing scale. Depending on the manufacturer, this equipment may be either battery or solar operated. Follow specific manufacturing guidelines for setup.

For hanging scales, pick a stable location that is able to support the weight of the scale plus the infant. The scale needs to be placed at a height that allows the infant to hang from the scale in the weighing pants without touching the ground. Follow specific manufacturing guidelines for setup. Certain scales are non-battery operated which is ideal for remote locations.  

Equipment Calibration
Known weights are used to calibrate scales. An example of how to calibrate infant scales is shown in this video.

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Smaller weights would be used to calibrate infant scales versus larger weights for standing scales that are used to measure older children. If weights are unavailable, using items of known weight (e.g., an unopened 20 pound bag of rice with the weight clearly labeled) can be used to calibrate equipment. Check the reading of the scale to ensure it measures exactly the same as the weight. If the measurement does not match between the scale and the weight, check the setup and location of the equipment and make any needed adjustments (e.g. some scales have a balance with adjustable feet that may assist with calibration). If the equipment is unable to be properly calibrated do not use it. Always be sure to record the calibration value prior to conducting any measurements. Once calibrated, the equipment should not be moved during a measurement session. If moved, the equipment should be re-calibrated. Calibration should occur at the start of each measurement session.

Equipment Care
Scales, especially infant scales, should be wiped down with sanitizer after every child’s measurement to prevent the spread of germs. Cleaning the equipment at the end of the session is also important to extend the life of the equipment. It is recommended to store equipment in a temperature controlled environment to maintain its integrity. There are also carrying cases available for transport.