Scitec 420 - 7 Using the 420 as a Single Phase Instrument to Take Quick Measurements

Boston Electronics Corporation, 91 Boylston Street, Brookline MA 02445
(800)347-5445 or (617)566-3821 * fax (617)731-0935 * boselec@boselec.com * www.boselec.com
Bartles Industrial Estate, North Street, Redruth, Cornwall TR15 1HR
Tel. (01209) 314608 E-mail: scitec@scitec.uk.com
Fax. (01209) 314609 Web: http://www.scitec.uk.com
7 USING THE 420 AS A SINGLE PHASE INSTRUMENT TO TAKE
QUICK MEASUREMENTS
This series of instructions uses the 420 as a single phase lock-in amplifier and just uses the X
channel.
(1) Connect up the lock-in amplifier.
(2) Switch the offset control (6) to off.
(3) Switch the 1F/2F switch (11) to that required.
(4) Switch the input sensitivity (1) to 1V.
(5) Switch the time constant (3) to 100mS.
(6) Switch both phase controls (9)(10) to 0°.
(7) Switch the output select switch (7) to X.
(8) Increase the sensitivity control (1) until a signal is seen at the output (13).
(9) If the output becomes noisy, increase the time constant setting (3) until the noise is
removed.
(10) Adjust the phase control dials (9)(10) until a maximum output is seen.
(11) Take your reading. The amplitude of the input signal is now available on the meter display
(13). The phase relationship between the input signal measured and the reference signal can
be read off the position of the phase control dials (9)(10).
This method of taking measurements is not optimal as it does not take into account any
instrument or signal offsets nor is it particularly accurate at setting the phase setting.