Apart from the obvious condition that the tester or testers doing Level of Consciousness (LOC) calibrations must each calibrate at least at 200 level, and the objective of testing is integrous, there are no other limitations.
However, the experience indicates that although the technique is absolutely objective, there are situations when testing may produce erroneous results. The list below is not in any way an exhaustive one; each practitioner’s experience will differ.

1.    Being physically tired.
2.    Highly emotional state.
3.    Failure to ask the permission.
4.    Statement being tested is formed incorrectly as a question.
5.    After listening to the rap, or similar music.
6.    Loud music in the background.
7.    Feeling dispirited.
8.    Testers are a married couple.
9.    There’s a personal interest in the outcome.

Whether a single person or a couple does the testing, the results should be the same. The same goes when different techniques are used: outstretched arm, weight lifting, or various techniques where different fingers are used to sense the muscular reactions. In fact, any muscles in the body can be used. Although practitioners of kinesiology use these techniques every day, it doesn’t make them supremely qualified to conduct LOC calibrations.

Each of the nine factors listed above will impact differently on the results, depending on the personality of the tester and most importantly, his or her LOC. Those with high LOC (500 and above) are deemed to be better “attuned” to Consciousness and less prone to error. Still, practicing and a sound mental attitude always help. Calibrating the same person/event/object repeatedly, say three tests spanned by a week each, will deliver results that are much closer to truth. In any event, saying a pray or invoking God’s Grace, can only help; as will dedicating the testing to the Highest Good.