ANSI/ESD STM7.1-2020 measures the electrical resistance of a complete electrostatic discharge (ESD) flooring system. It provides separate procedures for laboratory product qualification and acceptance of installed or applied floors. The testing stage determines the preparation, connections and measurements required.
Craftsman Concrete performs STM7.1 flooring-resistance testing when specified, using calibrated instrumentation and documenting the results against the project’s acceptance criteria. Testing is available for floors installed by Craftsman and other contractors. Our ESD floor testing services explain how testing and reporting can be arranged for your facility.
Choose the procedure for the testing stage
| Testing stage | Required resistance measurements |
|---|---|
| Laboratory product qualification | Resistance to a groundable point and point-to-point resistance on the flooring samples |
| Installed-floor acceptance | Resistance to ground and point-to-point resistance on the installed or applied flooring system |
The qualification and acceptance guides explain the preparation, measurement sequence and reporting requirements for each procedure.
Understand the method’s scope
STM7.1-2020 covers flooring systems with resistance greater than 1.0 × 10⁴ ohms and less than 1.0 × 10⁹ ohms. Both endpoints are excluded. This range describes the method’s scope; it does not establish the project’s acceptance limits.
Flooring forms within scope include floor mats, floor coverings, coatings, paints, raised access panels and floor finishes.
The test evaluates the flooring assembly
A flooring system includes the components required to carry static charge to ground, such as the surface material, adhesive, grounding mechanism and substrate. The measurement evaluates the assembled electrical path.
The explanation of what belongs in a qualification sample describes why testing the surface material alone may not represent the specified flooring system.
Interpret conductive and dissipative classifications
STM7.1-2020 defines these classifications using resistance to a groundable point:
- Conductive: less than 1.0 × 10⁶ ohms.
- Dissipative: greater than or equal to 1.0 × 10⁶ ohms and less than 1.0 × 10⁹ ohms.
Test voltage can affect the measured resistance of some materials. The guide to voltage-dependent flooring classifications explains why a material may cross the classification boundary when measured at different voltages.
Compare results in their testing context
Resistance to a groundable point measured on laboratory qualification samples may differ from resistance to ground measured on installed areas. STM7.1 specifically notes this possibility, particularly for materials such as floor finishes.
Before comparing results, identify the tested assembly, measurement connections, voltage and conditions. The explanation of why laboratory and installed-floor readings differ examines those influences.
The STM7.1 reporting requirements identify the records needed to document the tested system and its results.
Distinguish STM7.1 from ASTM F150
Both methods address flooring resistance, but their scopes and procedures differ. A result identified with one method should be interpreted under that method’s requirements.
The comparison of ANSI/ESD STM7.1 and ASTM F150 explains the differences relevant to selecting a procedure and reviewing results.
Recognize what a resistance result does not establish
Walking body voltage
Resistance is one property of an ESD flooring system. It does not establish the voltage generated by a person walking in a particular footwear/flooring combination.
See why floor resistance does not establish walking body voltage when determining whether additional system testing is needed.
Personnel and ignition safety
STM7.1 resistance measurements must not be used to determine the relative safety of personnel exposed to high alternating-current or direct-current voltages.
The method also excludes facilities where ordnance, flammables or explosives are stored or handled and refers those concerns to ASTM F150. That referral does not itself establish a flooring system’s suitability for the operation. The shock and ignition safety guidance explains the separate assessment required.
Frequently asked questions
A flooring system with resistance to a groundable point of exactly 1.0 × 10⁶ ohms is dissipative under STM7.1-2020. The conductive definition is below that value; the dissipative definition includes it.
No. The classification describes resistance to a groundable point. Installed-floor acceptance requires the applicable measurements and comparison with the project’s acceptance criteria. The classification also does not establish walking body voltage or personnel safety.