Yea, it might be nice to get an answer to this question with regard to my part the Codatron(TM, but the search resolved to some observations; the reason for this posting.
CE Marking is most probably required if you export to the 27 European Union (EU) and 3 European Free Trade Association (EFTA) member states. Of 20 groups of products, only those that might be applicable are stated below.
GROUP 3. Low Voltage Electrical Equipment DIRECTIVE 73/23/EEC >>General Discussion: INCONSISTENT! (if not generous, say "liars") In Scope, 2.3(a) "The Low Voltage Directive is not designed to impose safety standards." BUT this directive eXplicitly mandates "safety of persons, domestic animals or property".>Discussion: Compliant to 1a via Data Sheet, to 1b via label, to 1c being a completely assembled item (customer responsible thereafter), and compliant to 1d by design.>Discussion: Compliant to 2a, 2b, 2c and 2d by design.>Discussion: Compliant to 3a, 3b and 3c by design.>Discussion: The Codatron(TM) might be considered a "control component" only if a resistor or a diode or like item is considered as such. It is not a "protective system" as described, nor is it an "essential" component as described. However, "potentially explosive atmosphere" does indeed apply when used in downhole equipment, BUT a steel rod for drilling would be a better "fit" to this Directive. NOTE their improper tense and use of the word "Used".