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 condition.
 

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 product.

Metal Housings

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.

Finishing

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.

Mercury Reservoirs

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 sockets.
  
• 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 strains.
  

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.
 

Rubber Parts

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 available.

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.