OPERATION MANUAL - Scintrex

Operating the CS-3 in the FieldSummaryIf the CS-3 is properly oriented inside the active zone, defined by equations(1) and (2) in Chapter 3, “Orienting Your CS-3”, and the operatinghemisphere is not set properly either of following will happen:• There will be no Larmor signal at the output. By setting the operation to theproper operating hemisphere, the Larmor signal will appear.• There will be signal at the output, but not at the Larmor frequency. The falsemagnetic field reading will be higher than the true reading, obtained whenthe operating hemisphere setting is correct (about 60nT higher if the ambientfield is 60,000nT). In addition, it will be much noisier.The reason for this is the existence of another resonant line, smaller inamplitude and opposite in phase from the desired resonant signal. Theself-oscillation based on this signal can take place if the operatinghemisphere is wrongly selected. By setting the operation to the properoperating hemisphere, the true, lower value and less noisier, magnetic fieldreading will be obtained.The described alternative modes of controlling the operating hemisphere ofthe CS-3 are incompatible with the optional electronic control used in oldermodels of Varian and Scintrex magnetometers.The reversing of the magnetometer power supply polarity, used in these oldermagnetometer models, had certain disadvantages and it was abandoned in theCS-3. It is not difficult to change the existing installations by rewiring theswitch used for the power supply reversal and to make it perform levelcontrol required by the electronic control mode "R", as described in thissection, or by automatic hemisphere switching.2-8CS-3 Manual - part # 762701Revision 2.0