Cleaning Standards

Standards Conditions/Cleaning
All standards that are delivered to this laboratory must be submitted clean and, where required, painted. Cleaning and/or repair of standards in the metrology lab can be considerable and added to the calibration costs.

Precision Mass Standards

  • Precision Weights have very tight tolerances, thus requiring gentle handling and proper storage before, during, and after calibration.

  • Unless your management system prohibits, pre-clean each weight with a cotton swab and/or dust-less 'kim' wipe lightly dampened with ethanol. Let Air dry before placing back into their case.

  • Remove dust and other foreign objects from the cases.

  • All cases must be properly marked with an identification number. If this is missing, the laboratory will issue a generic identification.

  • When shipping individual weights, please pack each weight with tissue paper, NOT BUBBLE WRAP. Plastic-based packing materials will leave residues on weights.

  • For weights that are shipped inside of a case, please wrap the case with tape or rubber bands to prevent the case from opening and spilling the tiny weights in the box during shipping.



Non-Precision Mass Standards

  • Weights should be clean and in good repair. Except for weights that have been submitted to the laboratory in the past and have shown that they can maintain tolerance, all weights submitted must meet the requirements of NIST HB 105-1.

  • An ethanol-dampened rag cleans stainless steel weights well.

  • Interior cases for weight kits should be wiped down or vacuumed.

  • Cases should be sound with secure latches.

  • Cast Iron weights should have no evidence of rust, loose paint or adhering debris.

  • Do not "power wash" cast iron weights as this creates divots in the material, removes too much paint, and introduces water into the adjustment cavity. This can be considerable to the overall cost.

  • Light sanding with steel wool and wipe down with mineral spirits works well to clean cast iron.

  • Cast Iron weights should be painted with a light coat of aerosol paint.

    • Silver/Aluminum color for customary weights

    • Gold color for metric weights

  • Do not use epoxy or enamel paint.

  • During colder months, large cast iron weights should be kept indoors the night before calibration to keep them as close to room temperature as possible when arriving. We cannot calibrate weights that are wet.

  • Companies bringing in large weights should only drop off/pick up on Friday. Any other days, they will be refused unless pre-approved by a metrologist.

  • Weights should be identified with a permanent stamp or mark into the surface of the weight. Stickers are not allowed and will be removed.

  • If no permanent markings are present, the lab will issue a generic identification.

  • Handle your analytical weights carefully. Tolerances are small, so dirt or abuse can throw them out of tolerance. Adjustments add cost to your calibration.



Weight Carts

  • Make sure the cart is cleaned to remove debris, oil, and rust. Do not forget the tires.

  • Fill the gas tank to the specified reference line. This is usually an etched line into the gas sight tube.

  • Make all repairs/tune ups/replacements just prior to submitting the cart into the lab. Making changes to the cart in any way voids the current certificate and must be submitted back into the lab for recalibration.

  • Ensure all pieces of the weight cart are included when delivering the weight cart. For example, electric carts sometimes have an extension rod for the power cord. This is included in the overall calibration of the cart. Missing pieces extend the amount of time you are without your standard until we receive all parts.

  • If you make any major repairs/adjustments/replacements to the cart prior to submittal, let the metrologist know for record keeping purposes upon submittal. For example, if you add an extra spreader bar to the body of the cart, this is viewed as a major adjustment. Another example is if you have to replace the engine, gas tank, or hydraulic tank, this is viewed as a major repair/replacement. This not only helps us for record keeping, but it also saves time on calibration if we know if there was a significant change to the overall mass.



Dead Weight Testers

  • Weights should be clean of dirt, debris, and oil before sent to the lab for calibration.

  • All pistons should be complete with sleeves (if applicable). If the piston is incomplete or missing the sleeve, the piston will not be calibrated and will slow down the turnaround time until all parts are supplied.

  • All weights and pistons should be marked with a serial number or other identifying markings.

  • If no markings are present, the lab will issue a generic identification.



Volume Standards

  • Large volume provers and five gallon test measures must come in clean and painted if made of mild steel with no strong odors or evidence of hydrocarbons.

  • Any vessels with obvious residues will be refused and returned to the customer.

  • Be sure the prover has working valves, a clean glass gauge tube, and a readable gauge plate. Markings made by a permanent marker or anything other than the original etchings on the plate will not be accepted.

  • Be sure the mechanism for adjusting the prover can be moved freely.

  • Provers and test measures will not be tested if they come in with leaks, dents, or badly corroded interiors.

  • If any of the above conditions are found, the item will not be tested and will be returned to the customer for repair; please refer to NIST HB 105-3.



Time/Frequency Standards

  • Tuning forks should not be paired together with adhesive tape. Rubber bands, envelopes, and bags are excellent alternatives.

  • Tuning forks should be permanently marked with: frequency band, miles per hour rating and serial number.

  • LASER units should be supplied with batteries or car adapters that are fully charged.

  • Shipments of tuning forks and/or LASER units should be packed securely and include contact information.

  • Walk-ins are limited only to WEDNESDAY. Any other days must be pre-approved by a metrologist either using the request form or calling directly.

  • If a delivery is made other than Wednesday, we cannot guarantee that the equipment will be tested the same day.



Length Standards

  • A serial number or other identifying markings should be on the tape itself. Not on cases or boxes.

  • If no markings are present, the lab will issue a generic identification.