RR: 10 Routine Maintenance and Scale Calibration (New)

Effective Date: 12/11 Downloads: PDF Version    Revised Date: 07/15
   

Policy

As part of routine maintenance, scales will be well maintained and calibrated every 6 months at minimum. Calibration of scales is imperative to ensure clients weights are recorded accurately and education is tailored accordingly. The WIC Clinic Coordinator or a designated staff member will be required to keep the written record of equipment calibration using the “Calibration Log.” This log will be kept at the clinic and made available to the state as necessary for review purposes.

 

Procedure

I.  Proper maintenance of equipment includes:

a. Regular cleaning of equipment with soap and water.

b. Checking equipment for damage and loosening of joints (especially footboard and headboard if they no longer hold a right angle).

c.  Checking for readability of the gradations on the tapes.

d. Repairing or replacing damaged or defective equipment.

If equipment requires replacement or repair please contact the scale company vendor.

Scale Maintenance

II. Proper method for calibrating scales:

a.  Scales are to be calibrated every 6 months by using the standard weights supplied by the scale company vendor. Scale accuracy is tested by weighing a number of standard weights on each scale.

b.  Acceptable tolerance ranges for the scales are as follows (depending on precision of the scale):

  • Pediatric beam-balance scale: ¼ ounce to 1 ounce
  • Pediatric digital scale: ¼ ounce to 1 ounce
  • Adult beam-balance scale: ¼ pound
  • Adult digital scale: two tenths (0.2) to ¼ pound

c.  To check for accurate weighing of scales, use the standard weights to complete the following:

Digital Scales (NON MEDELA)

  • Turn the scale on and allow the scale to read “0” zero.
  • For a pediatric digital scale place a 5 lb. weight on the platform and allow the scale to stabilize. Read and record the displayed amount on the calibration log.
  • For an adult digital scale place 15 lbs. on the platform and allow the scale to stabilize. Read and record the displayed amount on the calibration log.
  • Remove the test weight and allow the scale to return to “0” zero.
  • Repeat by placing a larger weight amount on the platform (for pediatric scales use 35 pounds and for the adult scale use 75 pounds); allow the scale to balance. Read and record the amount on the calibration log.
  • If the scale cannot be balanced to both high and low weights, the scale is inaccurate, and needs to be balanced.

Digital Scales (MEDELA BABYWEIGH)

  • Medela scales require use of 2x 10 kg weights (44.2 lbs.)
  • With scale turned on, press the “1” button while the display is flashing until display reads “Func 1”.
  • Press “reweigh fed baby” button until display reads “Func 2”.
  • Press “3” button until display shows “9.XXX” (For example, 9.802 will be displayed)
  • Press “3” button again until display shows “20 0- -” and “g”. Wait for display “20 2- -”.
  • Place two 10 kg weights on the platform after the display shows      “20 2–”
  • Wait for the display to show “stabilized” mark (a circle in the top left corner), then press the “3” button to complete calibration.
  • Wait for display to how “func 1” then remove the 20 kg weight
  • Press “off” button to turn scale off.
  • NOTE: If an “Er- -” message displays, recalibration must be performed.
  • Do not leave the calibration weights on the scale for more than a few minutes.

Beam Balance Scales

  • Slide both sliding weights on beam to extreme left.
  • Check to assure scale is balancing in the “0” zero position. If the beam is not in the center of the indicator adjustments are needed (see manufacturer directions for balancing).
  • For a pediatric beam balance scale place a 15 lb. weight on the platform and allow the scale to stabilize. Read and record the displayed amount on the calibration log.
  • For an adult digital scale place 15 lbs. of weight on the platform and allow the scale to stabilize. Read and record the displayed amount on the calibration log.
  • Remove the test weight and allow the scale to return to “0” zero.
  • Place a larger weight amount on the platform (for pediatric scales use 35 pounds and for the adult scale use 75 pounds); allow the scale to balance. Read and record the displayed amount on the calibration log.

III.  Scale Recalibration

a.  If you find the accuracy of the scale is outside the tolerance specified by the manufacturer or outside the tolerance indicated in RR: 10, or you receive an “Er—“ reading (Medela scales ONLY) you should have the scale recalibrated. Some scales can be calibrated by the user, other scales may need a field technician or they may need to be sent back to the manufacturer for calibration.

b.  If there are issues contacting the scale vendor, contact the state office for assistance.