A resistance meter’s calibration interval and an electrostatic discharge (ESD) floor’s retest interval are separate schedules. The calibration interval determines when the meter is recalibrated; the floor’s verification frequency belongs in the organization’s ESD compliance verification plan. A meter manual specifying a one-year calibration cycle does not, by itself, mean the floor should be tested annually.
What a calibration interval schedules
Recalibration of the measuring equipment
The International Laboratory Accreditation Cooperation (ILAC) and the International Organization of Legal Metrology (OIML) published ILAC-G24/OIML D 10 (Edition 2022) to guide laboratories in determining and reviewing recalibration intervals for measuring equipment under their control. That guidance concerns the equipment’s calibration schedule; it does not establish how often an ESD floor should be tested.
A one-year calibration cycle in a meter manual
The Prostat PRS-801B/PRS-812B resistance meter user manual (Revision 9, July 19, 2026) says, under Calibration Information: “The resistance meter specifications are based on a 1 year calibration cycle.” That year is a condition of these meters’ published specifications. It is not an instruction to retest the floor every year.
What sets the floor verification schedule
The compliance verification plan under ANSI/ESD S20.20-2021
ANSI/ESD S20.20-2021 is the ESD Association’s program standard, approved by the American National Standards Institute (ANSI). Section 7.4 requires a compliance verification plan that identifies the ESD control items to be tested periodically and how often they are tested. The floor’s retest frequency belongs in that plan.
Who decides the interval, and on what basis
ESD TR53-01-22 is the ESD Association’s technical report on compliance verification. Its foreword places the interval decision with the organization performing the report’s compliance verification procedures. It recommends basing the intervals on how critical the ESD control items are to the organization’s ESD control program. The foreword is not part of the technical report itself; that basis for choosing intervals is a recommendation.
What to check before the next floor test
Check both schedules and document the floor interval
Check the meter’s calibration documentation to determine when recalibration is due. Check the facility’s ESD compliance verification plan to determine when the floor is due for testing. If the floor’s frequency is missing, have the person responsible for the ESD program establish and document it.
Craftsman Concrete Floors provides ESD floor testing with calibrated resistance meters and documents the equipment used, its calibration status, and the test results. Contact Craftsman to arrange testing or discuss a verification schedule for your facility.
Frequently Asked Questions
No. The calibration interval concerns recalibration of the resistance meter. Floor verification has a separate frequency, recorded in the organization’s compliance verification plan under ANSI/ESD S20.20-2021.
The organization performing compliance verification determines the interval. ANSI/ESD S20.20-2021 requires the compliance verification plan to identify periodically tested ESD control items and their frequency. The informative foreword to ESD TR53-01-22 recommends basing the interval on how critical the item is to the organization’s ESD control program.
No. ILAC-G24/OIML D 10 (Edition 2022) provides guidance on determining and reviewing recalibration intervals for measuring equipment. It does not establish an ESD floor testing frequency.