How many linear-log recorders in this picture?
Wrong.
Not one, but two. In our new Model DSRLG recorder, there are two independent linear-logarithmic channels, each with its own recording pen. So for all practical purposes, the Model DSRLG is (are?) two recorders in one. The benefits of this double life: When connected to spectrophotometers, photometers, densitometers, and the like, the Model DSRLG will record simultaneously both transmittance and absorbance. And when properly factory-equipped and then connected to a spectrophotometer with a transmittance output, the DSRLG will simultaneously record both absorbance and log absorbance (extinction coefficient).
There are other ways to put the DSRLG to work, of course. Such as recording absorbance as a function of a nonlinear variable (temperature, pressure, etc.) which is also recorded. Or recording, linearly or logarithmically, any two time-synchronized variables. So much for what and why. Now for how. The DSRLG uses precision, nonlinear gears to achieve logarithmic response. And that's a more accurate, truer method than electrical circuit approximations. (The log gears are quickly interchangeable with the linear gears.) You simply set the switches for automatic gain adjustment at all points in the log scale and for automatic divider zero-point.
Add in some of the DSRLG's other good points—all solid-state circuitry; circuit guarding to prevent interchannel communication and to reject A.C. and D.C. interference; seven switch-selected chart spans with continuously variable expansion of each from 100% to 40% ; three-speed synchronous chart drive; 240-mm wide chart; a pen response of less than 1 second; zener-diode-regulated reference circuits—add all of those points in, and you've got quite a dual-pen, linear-log recorder for $2075. Call your Sargent-Welch representative for a DSRLG demonstration. Or write to us for additional information. 9-228
SARGENT-WELCH
Scientific instruments, apparatus, chemicals. Sargent-Welch Scientific Company 7300 N. Linder Ave.; Skokie, Illinois 60076 Circle No. 63 on Readers' Service Card
Chicago/Anaheim/Birmingham/Cincinnati Cleveland/Dallas/Denver/Detroit Springfield, N.J./Toronto/Montreal/Vancouver
VOL. 4 1 , NO. 12, OCTOBER 1969
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