⚡ Measurement of the vertical resistance RV of protective clothing materials — specimen between a disc electrode with guard ring (as electrode type A of EN 1149-1) and a metal base plate, DC voltage (100 ± 5) V, reading with ohmmeter or electrometer after (15 ± 1) s; five specimens after conditioning at 23 °C and 25 % humidity, result — arithmetic mean in ohms, PN-EN 1149-2

Electronics and EMC PN-EN 1149-2

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 1149-2:1999 (Polish version), in full (our translation): “Methods for testing the vertical resistance of materials from which protective clothing is made are specified, in order to assess their antistatic properties required in explosion hazard zones”. We read the text of the standard in the sample of SIST EN 1149-2:1998 — a scan of EN 1149-2:1997 (August 1997) from the title page through the foreword and Clauses 0–9 to the end of the test report, read from the page images. Outside the sample remain the informative Annexes A (additional information, among others on other test atmospheres) and ZA (relationship with EU Directives).

ACCORDING TO THE TEXT OF EN 1149-2:1997 (foreword, Clauses 0–9). The standard was prepared by CEN/TC 162 “Protective clothing including hand and arm protection and lifejackets” (secretariat DIN); approved by CEN on 24 July 1997. Introduction (0): the standard is part of a series of test methods and requirements for electrostatic properties of protective clothing, divided into parts because of the differing fields of application and materials. Scope (1): test method for measuring the electrical vertical resistance of protective clothing materials; the standard is not applicable for specifying protection against mains voltages. Reference (2): EN 1149-1:1995 (surface resistivity — test methods and requirements). Definition (3.1): vertical resistance RV — the electrical resistance through a material in ohms as determined by using specified electrodes. Principle (4): electrodes are placed on opposite surfaces of the material, a DC potential is applied and the vertical resistance is determined. Apparatus (5): electrode assembly identical to electrode type A of EN 1149-1, which also determines the measuring geometry (Figure 1); test electrode — metal disc about 3 mm thick, diameter d1 = 50,4 mm, secured by a disc of high-insulating material concentrically in a metal guard plate, with a coaxial plug-in connection; annular electrode — metal guard ring about 3 mm thick, inside diameter d2 = 69,2 mm and outside diameter d3 = 89 mm, placed via a high-insulating ring in a screening ring of outside diameter d4 = 100 mm, with a connector insulated from the screening ring; base plate electrode — metal disc of (110 ± 0,2) mm diameter and about 12 mm thickness, with an insulating layer on the lower side of at most 1 mm and insulation not less than 10¹⁴ Ω, with a socket; the test electrode is concentric with the annular electrode and easily movable within it, and electrical contact between guard plate and screening ring is made by sprung balls in three holes equally spaced on the circumference — the spring pressure shall be weak enough for extra friction to be negligible; the electrode surfaces in contact with the specimen shall be of the same material so that with specimens containing electrolyte no electrolysis junctions occur; total mass of test and annular electrodes (1020 ± 20) g, exerting a contact pressure of about 10 N, and for equal pressure of both electrodes (about 0,225 N/cm² = 2,25 kPa) the mass of the test electrode (460 ± 10) g and of the annular electrode (560 ± 10) g; Figure 1 gives dimensions for steel metal parts (density 7,8 g/cm³) and insulating parts of PMMA, PS or PC (about 1,19 g/cm³). Ohmmeter (5.2): range 10⁵–10¹⁴ Ω, error limit ± 5 % up to 10¹² Ω and ± 20 % above; alternatively an electrometer with an input impedance of not less than 10¹⁴ Ω and a separate DC source with an inbuilt safety resistor. Cleaning agent (5.3): e.g. propan-2-ol or ethanol (note — they are highly flammable and toxic; collective or personal protective measures against ignition, breathing of vapours and contact with skin, eyes and clothing are recommended). Specimens (6.1): from a sample or garment five specimens are cut, of a size between the overall dimensions of the annular electrode and the base plate; when testing a garment, measurements are made at five different suitable places; specimens are handled only at the edges to avoid contamination (note — specimens may come from the same production lots as the materials used for the delivered clothing). Conditioning and test atmosphere (6.2): at least 24 h before testing and testing at an air temperature of (23 ± 1) °C and relative humidity of (25 ± 5) %; note — other atmospheres may be required for specific purposes (Annex A). Procedure (7): the lower surfaces of the test and annular electrodes and the upper surface of the base plate are wiped with a paper tissue moistened with the cleaning agent; the insulation of the base plate is tested according to 5.4.2 of EN 1149-1:1995; the base plate is placed with the non-insulated side up, the material on it and the test and annular electrodes concentrically on top; the circuit is connected according to Figure 2; if the surface resistivity of the sample according to EN 1149-1 is less than 10⁸ Ω, the metal guard ring is not earthed during determination of RV, as otherwise an excessive fault current may unduly reduce the test voltage — in that case only specimens, not garments, are tested; a potential of (100 ± 5) V is applied and after (15 ± 1) s the vertical resistance is determined; for a resistance below 10⁵ Ω an appropriate low voltage may be applied and stated in the report, and if necessary the resistance may be determined as the ratio of the voltage to the current measured with an ammeter in series with the specimen; the procedure is repeated on the four other specimens or at four other places on the garment. Calculation (8): arithmetic mean of the five measured values of vertical resistance. Test report (9): reference to the standard, description of the material, test atmosphere, test voltage in volts, all five single measurements, mean vertical resistance RV in ohms, deviations from the standard, date of test.

STATUS (catalogue card as of 03.10.2026). The card of PN-EN 1149-2:1999 (Polish version, published 16-11-1999, 11 pages, price group F) has no “Withdrawn” header: Electrotechnical Sector, KT 143 Static Electricity, ICS 13.340.10, “Introduces: EN 1149-2:1997 [IDT]”, “Additional elements: PN-EN 1149-2:1999/Ap1:2001”. The PKN search engine (query “PN-EN 1149-2”, 03.10.2026) shows only this edition. European document: the Slovenian SIST EN 1149-2:1998 (identical to EN 1149-2:1997) has the status “Published” in the iTeh catalogue (read 03.10.2026); we found no newer edition of EN 1149-2 in the catalogue. We have not read the content of correction Ap1:2001.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 03.10.2026). The number 1149-2 appears in 8 records at 7 laboratories: AB 005, AB 128, AB 154, AB 164, AB 374, AB 665, AB 1710. In the current scopes on the PCA website (read 03.10.2026, issues from 05.09.2023 to 14.07.2026) AB 005 and AB 1710 give “PN-EN 1149-2:1999” (AB 1710 also “EN 1149-2:1997”), AB 154 and AB 164 — “PN-EN 1149-2:1999+Ap1:2001”, AB 374 — the 1999 edition and separately correction Ap1:2001, AB 128 and AB 665 — the designation alone without date. The “Laboratories” tab (“PN-EN 1149-2”) shows all 7 laboratories; checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA scopes). “Vertical resistance” of protective clothing and its materials (AB 005 also of gloves and footwear, together with PN-EN 16350:2014-08), of flat textile products (AB 154) and of materials and products whose electrification may pose a hazard (AB 374). Ranges: from 1×10³ to 1×10¹² Ω (AB 005), from 500 Ω to 1,0×10¹⁴ Ω (AB 1710), (2×10³–2×10¹⁴) Ω at measuring voltages of 10, 100, 250 and 500 V (AB 154), (0,1–2×10¹⁴) Ω and (2×10³–2×10¹⁴) Ω in two items of AB 164, (1–10¹⁰) Ω (AB 374). Next to it are surface resistivity according to PN-EN 1149-1 and charge decay time according to PN-EN 1149-3.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Voltage and range: the standard provides for 100 V and an ohmmeter of 10⁵–10¹⁴ Ω; a lower voltage only for a resistance below 10⁵ Ω and stated in the report (7.3) — the voltages of 10, 250 and 500 V and ranges from 0,1 Ω or 500 Ω in PCA scopes go beyond the basic conditions of the standard, and the test voltage must be stated in the report (7.3, 9 c)). Reading time: the resistance is read after (15 ± 1) s — a reading at another moment after applying the voltage does not meet 7.3. Climate: 24 h conditioning and testing at 23 °C and 25 % humidity (6.2) — a result obtained at another humidity does not meet the condition of the standard; other atmospheres only for specific purposes (Annex A, which we do not have). Guard ring: with a surface resistivity below 10⁸ Ω the ring is not earthed — otherwise fault current reduces the test voltage; garments are then not tested (7.3). Electrodes: the masses of (460 ± 10) g and (560 ± 10) g give a pressure of about 2,25 kPa — other electrodes mean another pressure; contact surfaces of one material, clean, wiped with the cleaning agent (5.1.5, 7.1); specimens are touched only at the edges (6.1). Result: the result is the arithmetic mean of five values (8), and the report must give all five values, not only the mean (9).

WHAT WE DO NOT GIVE. We do not have Annexes A and ZA or the content of correction Ap1:2001 — so we give neither other test atmospheres, information on the relationship with EU legislation nor the changes introduced by the correction. The standard (read in full except the annexes) gives no requirements for vertical resistance and no precision of the method — so we do not give them either.

Method principle

The material specimen is placed on a metal base plate, and on it concentrically a disc electrode with a guard ring; a DC voltage of 100 V is applied between the electrode and the plate and after 15 s the resistance through the thickness of the material (vertical resistance RV) is determined with an ohmmeter or electrometer; the result is the arithmetic mean of five specimens or five places on the garment.

Applications

• Materials and finished protective clothing with antistatic properties — among others for explosion hazard zones (scope of the PKN card); 7 laboratories in PCA scopes
• Flat textile products and materials and products whose electrification may pose a hazard — in PCA scopes
• Tests together with surface resistivity (PN-EN 1149-1) and charge decay time (PN-EN 1149-3)

Key parameters

Standard

Standard number

PN-EN 1149-2:1999 + Ap1:2001

Title (PL)

Odzież ochronna — Właściwości elektrostatyczne — Metoda badania rezystancji skrośnej

Title (EN)

Protective clothing — Electrostatic properties — Part 2: Test method for measurement of the electrical resistance through a material (vertical resistance)

Step-by-step procedure

1. Specimens and conditioning

   Five specimens sized between the annular electrode and the base plate (or five places on the garment), handled at the edges; ≥ 24 h at (23 ± 1) °C and (25 ± 5) % RH. PN-EN 1149-2:1999 + Ap1:2001 current (PKN catalogue card as of 03.10.2026).

2. Electrode preparation

   Wipe the contact surfaces with a tissue moistened with propan-2-ol or ethanol; check the insulation of the base plate according to 5.4.2 of EN 1149-1:1995.

3. Measuring set-up

   Base plate with the non-insulated side up, the material on it, test and annular electrodes concentrically on top; circuit according to Figure 2; at surface resistivity < 10⁸ Ω do not earth the ring.

4. Measurement

   Apply (100 ± 5) V, read RV after (15 ± 1) s; below 10⁵ Ω — lower voltage (record it) or ammeter; repeat on the other four specimens or places.

5. Result

   Arithmetic mean of five RV values in ohms; report with atmosphere, voltage and all five results.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Propan-2-ol and ethanol are highly flammable and toxic — the standard recommends protection against ignition, breathing of vapours and contact with skin, eyes and clothing (note to 5.3)
• The standard is not applicable for specifying protection against mains voltages (1) — the result does not prove insulation of the clothing against electric shock

Frequently asked questions