INSTRUMENTATION
Transmission Type Fluorimeter Model
500
read-out potentiometer is balanced manually until t h e galvanometer reads zero. I n t h e eight- a n d twelve-com ponent instruments, this operation is entirely automatic and as each com ponent is interrogated a servo-system effects a balance and the percentage appears directly on the digital read-out potentiometer. Experience h a s shown t h a t the compositions calculated by means of this computer agree t o within 0 . 1 % with the composition calculated b y means of a - d e s k calculator. T h e potentiometers used for peak areas must have a linearity of 0.05%. T h e effect of ''loading" on t h e potentiom
eters used for calibration constants is eliminated b y t h e use of t h e read-out potentiometer for setting the calibra tion constants into t h e instrument. Because of the effect of loading on these potentiometers, no digital dials are used on the calibrating potentiom eters. I n repetitive analyses, t h e cali brating pots are set once and presum ably need only an occasional check. Although t h e word " c o m p u t e r " is a p t to suggest a multimillion-dollar installa tion, this example shows t h a t relatively simple analog devices are i m p o r t a n t a n d useful a n d they find increasing use b y the modern analyst.
Q
Applications Geochemical prospecting Uranium ore assay Control in processing and milling Uranium waste disposal investigations Urinalysis for uranium Distinctive Direct
Features
reading
Digital dial
Figure 2. Computagram Model 4075-4. ( A ) Digital area dial. (B) Calibra tion constants. ( C ) Meter sensitivity. (D) Calibrate-run switch. (E) Meter galvanometer. (F) Digital readout dial. ( G ) Component selector switch. ( H ) Power supply
read-out
High sensitivity Excellent High
linearity
resolution
Self-contained a n d compact Low
background
CAL·/β*?Α Γ/ΟΛ/
Recessed calibration D a m a g e proof
COsjs~rA/vr
controls
galvanometer
Regulated U-V source
K-//
xA,J
CALtBKArE:
(Σ
C~A~)
Specifications \ L
Range: From less than 1 0 - ' grams to 10~ 5 grams of Uranium.
1
(OsxAa)
Write for complete
BALL BROTHERS RESEARCH CORP. COLORADO
Circle No. 139 on Readers' Service Card
68 A
·
D/G/rAL.
XT
information ~m
BOUIDER,
C~A~)
ANALYTICAL CHEMISTRY
AM^l^/f^fE:*^
(CiaxAiz)
SCHEMAr/C
O/AG/^AM Figure 3
COM/^urAG/^AM
œerAoour
