Arlene,
Here are a couple of suggestions:
1. Tell him no. You are well within your rights in doing this. His device is a galvanometer and is a form of lie detector. He will therefore need a court order to force you to submit to it. He ain't got one.
2. Tell him that since Scientology is a religion he is asking you to subject yourself to a religious act. This is a violation of your civil rights. If he insists that you do so on the basis of his authority as your supervisor both you and your lawyer will make so much money that you won't have to work for a while.
(btw, be sure to write this incident down and keep a record of it. Also, be sure to tell a couple of other reliable people about it. If it happens again, you are being harrassed. Records are important in such cases. )
3. Tell him that your religious beliefs are not a matter you wish to discuss at this time.
4. Ask him if Jesus is the Son of God. If he says, "no", ask him if that means HE is narrow minded.
5. A more diplomatic version of #4 is to ask, "What does it mean to be narrowminded?" He probably doesn't know and will fall back on something like "Its a refusal to consider new ideas." If he says this, ask him if he will prayerfully read the Gospel of John. If he says no....!
6. All of the above are merely options. You should pray about it and respond with a combination of boldness, tact, and sincere care for this lost and decieved man.
Blessings,
Thomas Maddux