the EDITOR'S column
The Improved Welch
CATHETOMETER For Precise Measurements
L.T. H a l l e t t , E d i t o r
IN AN ERA of jet-speed progress in the chemical industry, there are indications t h a t t h e analytical chemist has not been a leader in the field of on-stream analysis. On t h e basis of his observations a t a conference on automatic process monitoring a n d several years' experience in the field of continuous automatic analysis, Sidney Siggia, Oliii Mathieson Chemical Corp., feels t h a t this is a n analytical field which is almost devoid of analysts. As chairman of t h e conference, sponsored by t h e New York Academy of Sciences, D r . Siggia h a d a n opportunity t o note t h a t t h e m a jority of the speakers who discussed various phases of on-stream analysis were not analytical chemists, y e t this field is analysis, b y any definition. T h e dominant element a t t h e conference, both speakers and audience, consisted largely of electronic experts and electrical, chemical, and instrumental engineers. Also present were physical and organic chemists, biologists, m a t h e m a t i cians, computer experts, and salesmen, plus about 10% analysts. Continuous qualitative or q u a n t i tative monitoring of chemical systems involves automatic measurement of physical or chemical p r o p erties directly in or in attachments to the process equipment. Involved in this area are practically all analytical approaches such as absorption spectroscopy, electrical properties ( p H , e.m.f., conductivity, capacitance), thermal properties, physical properties (density, refractive index, viscosity), gas chromatography, colorimetric a n d volumetric analysis, gas analysis, mass spectrometry, and some others. As chemical technology progressed, continuous manufacturing processes increased and batch operations decreased. Continuous
R a p i d Leveling — F i n e E l e v a t i o n A d j u s t m e n t G r a d u a t i o n s E n g i n e D i v i d e d for Uniformity and Accuracy Vertical Range Smallest Reading by Vernier Telescope Working Distance Angular Magnification
100 cm 0.05 mm 45 cm to Infinity 1 2 X at 45 cm 8 X at Infinity 90-degree crosshairs 50 Seconds
Reticle Level Sensitivity
The latest improved design of the Welch cathetometer possesses a combination of features not hitherto available in an inexpensive instrument. It can be leveled and placed in proper adjustment easily and rapidly, yet all adjustments have sufficient sensitivity and delicacy of control to please the most meticulous user. It is intended for measurements and observations in both industrial and educational laboratories wherever an inexpensive instrument of good precision is needed. It is rigidly constructed and every essential adjustment can be made simply and positively. No. 68A—Each $257.50
THE WELCH SCIENTIFIC COMPANY ESTABLISHED 1 8 8 0
1515 Sedgwick St., Dept. A-1, CHICAGO
10, ILL., U.S.A.
Manufacturers of Scientific Instruments and Laboratory Apparatus
new
HEVI-DUTY
CIRC
THERM OVEN
Temperatures
to 250° C. (480° F.) I m p r o v e d T e m p e r a t u r e Uniformity. With Hevi-Duty's "circleof heat" design, there are no cold corners. Fast Heat-Up. T o 200° C. in less than one hour. Low-Cost Operation on either 115 or 230 volts. Selector switch permits high or low input to enclosed heating elements. Durable D o u b l e - W a l l Construct i o n . Steel outer shell is prime Model
Price
HK HL
$169. $265.
Overall Dimensions
Chamber Size Diameter
Depth
15 20
13 18
coated on both sides to prevent corrosion. Accurate T e m p e r a t u r e Control by sensitive bulb-type thermostat permits little lag or overshoot. For complete information, write for Bulletin 458.
Walts
Volts
000 1000
115/230 115
Width
Depth
Height
Shipping Weight
20 25
18 23
23 28
80 100
HEVI-DUTY A
DIVISION
HEVI-DUTY
OF ELECTRIC
BASIC COMPANY,
PRODUCTS
CORPORATION
MILWAUKEE
1, W I S C O N S I N
Industrial Furnaces and Ovens, Electric and Fuel · Laboratory Furnaces · Dry Type Transformers · Constant Current Regulators Circle No. 74 on Readers' Service Card
VOL. 33, NO. 1 JANUARY 1961
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71 A
