A. Insulation resistance
The Insulation Resistance (IR) of the mat, checked with a 5000V Meggar, should be 100,000 MΩ. A simple way to test: dip the mat in water for 24 hours at room temperature, then check IR on a 150mm × 150mm sample using two electrodes (25mm and 75mm diameter) after one minute of applied voltage. Crossing this IR value confirms a highly insulated mat, safe for anyone operating or handling equipment in switchgear and control rooms.
B. AC proof voltage
| Class | Voltage range | Thickness | AC proof voltage |
|---|---|---|---|
| A | Up to 3.3 kV | 2.0 mm | 10 kV |
| B | 3.3 kV to 11 kV | 2.5 mm | 22 kV |
| C | 11 kV to 33 kV | 3.0 mm | 36 kV |
A 1270mm × 1270mm sample of the relevant thickness is drawn per the table above. The test equipment has a 762mm × 762mm opening at its center, filled with a sponge soaked in a conductive liquid (water). The mat sample sits above the wet sponge, with a grounded metal plate on top — the wet sponge and grounded plate act as electrodes. The pad is then energised with the test voltage from the table.
- Type test: conducted for 3 minutes
- Routine test: conducted for 1 minute
If the mat passes the AC Proof Voltage test for these durations, it meets the safety requirements to prevent burn injury or worse from high voltage. A flashover may be visible during the test — this indicates the current is not being conducted by the mat.
C. Leakage current
Leakage current is measured during the AC Proof Voltage test. The allowable limit is 10 mA. Electromat mats achieve leakage as low as 0.7 mA — near negligible.
D. Thermal properties
i. Flame retardance
A 150mm × 150mm test piece is placed above a 20±2mm blue flame from a 9.5mm nozzle for 10 seconds, then withdrawn. The fire should extinguish within 5 seconds. Electromat extinguishes in under two seconds — even when the flame is left applied until burning starts (a harsher, more realistic test than the standard requires), the same result holds. Mats can also be produced with low smoke and low oxygen index parameters on request.
ii. Effect of acids, alkalis, diesel and transformer oil
Safety mats in real installations are routinely exposed to acids, alkalis, oils and diesel present in industrial and utility settings. Such exposure typically degrades rubber mats quickly, causing them to break apart. The test: immerse the sample in each medium (30% concentrated acid, 30% concentrated alkali, diesel, and transformer oil) for 48 hours at room temperature, dry for 4 hours, then check tensile strength and elongation. Values should not change by more than 20% — a critical quality checkpoint.
iii. Extreme low temperature
For countries with low temperatures, mats can be produced for performance down to −40°C / −104°F, subject to the specified test requirements.
E. Insist on independent verification
Because this product relates directly to worker safety, we advise users to insist on suitable testing — either at their own quality-control laboratory or at an outside agency such as ERDA-Baroda or the CPRI Test Lab at Noida.