No. This is what the Wikipedia page says for measuring sexual response in pedosexuals:
> In one study, 21% of the subjects were excluded for various reasons, including "the subject's erotic age-preference was uncertain and his phallometrically diagnosed sex-preference was the same as his verbal claim" and attempts to influence the outcome of the test.[28] This study found the sensitivity for identifying pedohebephilia in sexual offenders against children admitting to this interest to be 100%. In addition, the sensitivity for this phallometric test in partially admitting sexual offenders against children was found to be 77% and for denying sexual offenders against children to be 58%. The specificity of this volumetric phallometric test for pedohebephilia was estimated to be 95%.
> Further studies by Freund have estimated the sensitivity of a volumetric test for pedohebephilia to be 35% for sexual offenders against children with a single female victim, 70% for those with two or more female victims, 77% for those offenders with one male victim, and 84% for those with two or more male victims.[30] In this study, the specificity of the test was estimated to be 81% in community males and 97% in sexual offenders against adults. In a similar study, the sensitivity of a volumetric test for pedophilia to be 62% for sexual offenders against children with a single female victim, 90% for those with two or more female victims, 76% for those offenders with one male victim, and 95% for those with two or more male victims.[31]
> In a separate study, sensitivity of the method to distinguish between pedohebephilic men from non-pedohebephilic men was estimated between 29% and 61% depending on subgroup.[27] Specifically, sensitivity was estimated to be 61% for sexual offenders against children with 3 or more victims and 34% in incest offenders. The specificity of the test using a sample of sexual offenders against adults was 96% and the area under the curve for the test was estimated to be .86. Further research by this group found the specificity of this test to be 83% in a sample of non-offenders.[32] More recent research has found volumetric phallometry to have a sensitivity of 72% for pedophilia, 70% for hebephilia, and 75% for pedohebephilia and a specificity of 95%, 91%, and 91% for these paraphilias, respectively.
These systems work! And, while scary, or invasive, or not 100% accurate, this is no argument to reason that they don't.
"Measuring sexual arousal: https://en.wikipedia.org/wiki/Penile_plethysmograph & https://en.wikipedia.org/wiki/A_Place_for_Paedophiles" certainly seems to support the first claim: "The fruit machine was reincarnated for pedosexuals: a device attached to their genitals measures if they get sexual arousal from pictures of children. Those that do are not deemed ready for rehabilitation."