Why is the Baumanometer® sphygmomanometer the instrument of choice?
It's our attention to detail in the manufacture of our products and our
customer service that have earned the W. A. Baum Company its reputation as a
leader in the industry. Our meticulous approach to the manufacture of
Baumanometer® instruments is evident in every one we make.
To ensure the performance of our products, we teach distributors how to perform
preventive maintenance, replace accessory parts, and make repairs, which might
be required during the long useful service life of a Baumanometer®
instrument. We also make available a Baumanometer® Service Manual and a
Service Kit to enable hospital personnel to keep Baum equipment in good
Since we are concerned that our instruments are correctly used, we publish -
and make available at no charge - an authoritative teaching-aid booklet on
blood pressure measurement technique. One of these booklets is packed with each
of our instruments.
Attention to detail is evident in every part and every aspect of a Baum
First, the housings on our folding case models (Kompak and Desk), the body of
our Standby® and the housings for our Wall Unit 33 are all made of metal -
either aluminum alloy die-castings or extrusions. Although these components
cost much more than plastic substitutes and require many costly machining
operations, they are not affected by heat, chemicals, solvents or abrasion and,
therefore, endure without warping or losing their shape or their ability to
function correctly during many years of hard use.
The finishing (milling, drilling, threading, broaching, grinding, sanding,
polishing, de-greasing, painting, assembly, testing) of these components is
done by skilled operators with tooling developed during more than eighty years.
In addition to operations performed by others (we do not produce castings or
extrusions or dip latex parts, sew cuffs or make screw-machine parts) our
people perform an average of 125 operations on each Baumanometer® model.
All our mercury reservoirs have a large diameter, which, in combination with
large-bore calibrated tubes, assure long-term, trouble-free operation. On all
models where the reservoir/bracket assembly is not protected by a metal housing
(Panel Wall Model, Hi/Lo®, Kompak and Desk Models) this assembly is made
of metal (steel shell and malleable iron bracket). All our reservoirs contain a
stainless steel nozzle or "snorkel" extending to the center of the reservoir.
This is crimped to provide a narrow, slit-shaped access for cuff pressure. This
nozzle is covered with a stainless steel clip. Such construction prevents
escape of mercury through the reservoir nipple.
Mylar®-Clad Glass Tube
Our Mylar® Clad calibrated cartridge tubes are made of glass, not plastic.
Glass is optically clear, easy to clean, abrasion resistant and is more stable
than plastic. Plastic also has an affinity for mercury, which adds to the
friction between the mercury column and the inner wall of the tube. Combined
with the small bore used in plastic tubes, resistance to flow can change the
apparatus from a gravity manometer to an air compression gauge, producing
grossly erroneous readings. This phenomenon can be easily demonstrated.
Other advantages of our glass tubes are not obvious to the casual observer, but
are, nevertheless, very important. These include the following:
- Ends are tooled to provide raised collars for precise fit in tube
- End faces are flame-glazed to prevent chipping and to make firm contact
with tube socket washers.
- Ceramic lines are fused to the surface of the glass and cannot be removed
with chemicals, solvents or even by abrasion.
- Tubes are thoroughly annealed to eliminate both ring and longitudinal
Since 1995, all of our glass cartridge tubes have been further enhanced by a
unique process which involves the application (using heat and pressure) of
several layers of very strong, crystal clear Mylar® film which strengthen
the tubes and maintain its structural integrity even if the inner glass is
broken. Tubes are resiliently mounted with a spring-loaded slide assembly to
keep constant pressure at the tube sockets to prevent leakage of mercury.
Tubes are fully recessed behind the metal scale.
Baum cartridge tubes are guaranteed to be accurately interchangeable with other
tubes of our manufacture intended for the same model instrument. They can be
purchased at nominal cost as "spares" or the tube will be replaced without
charge if it is ever broken.
Filter Cap Assembly
The Baumanometer® Filter Cap Assembly is unique. Other manufacturers use a
wide variety of filter materials for this application - including cotton
wadding, blotting paper, plastic foam and the like; these materials often do
not function correctly for very long. Our filter material is selected for
exactly the right degree of porosity to permit the flow of air through the
opening in the filter cap, but to absolutely prevent escape of mercury through
the filter. One excellent result of this small but critical detail is the very
fast response of the mercury column to pressure changes in the cuff. Because of
the unique construction of our filter, it is also impossible to force mercury
into the filter (when this happens with other filters presently in use in other
instruments, escape of air above the mercury column is retarded or prevented
and erroneous readings will result).
Air-Flo® Control Valve
The Baumanometer® Air-Flo® Control Valve has several unique features
which make it function better and last longer than other valves intended for
the same purpose. The air-check mechanism in our valve utilizes a contact made
of silicone rubber with a smooth, convex surface for perfect fit against the
valve seat. This contact piece is kept snugly in place against the valve seat
by means of a stainless steel spring. This not only makes the valve work better
at low pressures, but also makes cleaning and replacement of the air-check a
very simple, quick procedure. This feature alone can add years to the service
life of the Air-Flo®. The air relief system also uses a stainless steel
spring and pin which are operated by a micro-threaded, knurled nut to provide
smooth, even release of cuff pressure at the recommended rate of 2 to 3 mm Hg
per heartbeat. All screw-machine parts are turned out of brass and are nickel
and chrome plated. Attachment of the rubber bulb is by means of a threaded
adapter; the neck of the bulb is protected against stretching by means of a
chrome-plated brass collar. These latter details assure firm attachment of the
bulb to the valve and extend the useful service life of the bulb.
Baumanometer® Rubber Parts are made of smooth, soft latex - fabricated by
the dipping process for seamless construction. They are protected against
accelerated aging by means of effective anti-oxidants and anti-ozonants
compounded in the liquid latex. "Latex-Free" (Neoprene) parts are also
Calibrated® V-Lok® Cuff
The Calibrated® V-Lok® Cuff is made to our rigid specifications of
specially woven Dacron® polyester fabric. It is stain resistant and
dimensionally stable. The index and range lines printed on the cuff immediately
indicate whether the correct size cuff is being used. Any of our six sizes can
be applied with equal ease and effectiveness on either right or left limb.
Velcro® hook and loop fasteners are used to provide the optimal number of
open-close cycles. Installation of the inflation bag requires threading tubes
through special openings and tucking in a flap to prevent bulging of the rubber
bag at the critical tube-joint area. This extends the useful life of the bag.