IEC 60079-14 & 25 both refer to the condition of lumped L & C for the field device (instrument) and not the distributed parameters of the cable. However, when halving the Co & Lo values for the associated apparatus, the calculation will then consider the external values for the field device and the cable with the consequences that the maximum acceptable cable length would be shortened. Is this a correct understanding of the principle? IEC 60079-14 mentions that the cable parameters shall be adjusted, IEC 60079-25 doesn't seem to have the same requirement.