PRINCETON APPLIED RESEARCH CORPORATION Box 565, Princeton, New Jersey 08540 | Gentlemen:
MEASURING SMALL SIGNALS IS NO LONGER A BIG PROBLEM
I Please send literature describing P.A.R. lock-in amplifiers I • for current application; Π for reference only. ! Π Please have a P.A.R. applications engineer contact me. | Π Please arrange a lock-in amplifier demonstration.
I
. Title.
Name. I Organization-
I ι Address I City
.State.
.Zip.
I Telephone.
Spending long hours trying to measure microvoltlevel signals? Chances are, you can cut the time to minutes with a P.A.R. lock-in amplifier. P.A.R. lock-ins are eliminating noise pollution in hun dreds of applications from bridge null detection to measuring light from stars. Our most versatile lock-in, the Model 124, has been used with an accessory transformer to measure signals as small as 5 picovolts. Other features include: • Continuously tunable frequency range from 0.2 Hz to 210 kHz • Automatic tracking of reference signals • Low-noise plug-in preamps to match a variety of source impedances • Dynamic range/drift tradeoff for wide applications flexibility The Model 124 is priced at $3150 including Model 117 preamplifier; other P.A.R. lock-ins range from $995. A complete line of accessories is available including light choppers, preamplifiers and trans formers. Also available is a new high-gain, current amplifying plug-in useful in low-level photometric applications. To arrange a no-obligation demonstration, or dis cuss your signal measuring problem, mail the cou pon above or call Hugh Doherty, Manager, Signal Processing Instrumentation, at (609) 452-2111.
CIRCLE 145 ON READER SERVICE CARD
16 A
·
ANALYTICAL CHEMISTRY, VOL. 43, NO. 6, MAY 1971
I