Better than other stills – Constructed of high-technology, chemically resistant glass and plastics, the 103S Still out performs other laboratory stills, including so-called double or triple stills, by a wide margin, because it has been carefully designed to take full advantage of the distillation process – just look at it.

• The most striking feature of the 103S Still is its compound condenser, which combines a hot-finger heat exchanger with a counter-current column. This unique condenser enables the103S Still to remove volatile contaminants hundreds of times more efficiently than coil or water-jacket condensers.
  
  
• A dual-action (hydrophobic/hydrophillic) transition stage between the boiler and condenser stages of the 103S Still corrects for any non-ideal conditions in the boiler. The hydrophilic steam filter traps mist and equilibrates overheated pockets of steam. A long hydrophobic barrier of virgin Teflon^® blocks surface entrainment by preventing the films of water on the glass surfaces of the boiler and condenser stages from communicating.
  
  
• 103S Still boilers are designed with a large water surface area and horizontally positioned heaters to promote gentle boiling and thereby, minimize the formation of mist and overheated pockets of steam. A magnetic water level sensor makes it possible to accurately regulate the flow of boiler feed water and avoid overflow. Overflow is a poor way to keep a still boiler clean and it increases the concentration of volatile water contaminants in the steam. The level sensor also plays a key role in the control of the efficient automated drain and rinse cycles that keep 103S Still boilers clean.
  
  
• Sophisticated, solid-state controls make the 103S Still simple to operate and permit unattended operation without sacrificing product water quality. Other stills lack essential controls and the quality of the water they produce falls dramatically during unattended operation.

A complete discussion of laboratory water still design, Design of Laboratory Water Still Systems, can be found under the Articles > Articles menu button on the Lab Water References page.

Better than cold-technology systems – The 103S Still also out performs systems based on cold technologies (e.g., filtration, reverse osmosis, batch ion exchange, electrodeionization, carbon sorption, UV, etc.). It consistently produces water of very high purity, it requires no expendables that must be monitored for failure or exhaustion, and it costs virtually nothing to operate when utilities are part of fixed overhead. Properly applied, cold technologies can be very effective; however, microorganisms proliferate; membranes foul and degrade; ion exchange and carbon sorption beds exhaust, shed particulates, and bleed organics; UV sources become coated and weaken; . . . . In order to achieve their potential for producing water of high purity, cold-technology systems must be intensively monitored and carefully maintained. A single resistivity meter will not detect the majority of discrete component failures that are likely to occur. Resistivity only measures mobile ions, so most contaminants are not detected. 18 MΩ-cm water is likely to be significantly contaminated. But the cost of necessary monitoring equipment, such as additional resistivity meters, total organic carbon (TOC) meters, UV meters etc., and effective maintenance is prohibitive for laboratory-scale systems. The cold technologies are simply not well suited for producing high purity water on a laboratory-scale.

For in-depth discussions on this important subject see Water Purification Technologies in Perspective under the Articles > Review Articles menu button on the Lab Water References page. The application notes in the new Ad Hoc water standard, AH/LabWater-1, are more concise and also extremely informative – select the Ad Hoc menu button on the Lab Water Standards page.)

• Self-cleaning and Self-sanitizing;
• Continuous performance monitoring with diversion of any product-water produced during sub-optimal conditions;
• Controlled response to fluctuations, or loss, of water pressure (tap water or pretreated) or AC power voltage; and
• Complete shut down, including feed and cooling water, when all attached containers are filled.

For in-depth discussion of the importance of true, full automation, see Design of Laboratory Water Stills under the Articles>Still Design menu button on the Lab Water References page.

• It is essentially insoluble in high-purity water (femto-moles silica);
• It can be fabricated into the necessarily intricate shapes and flawless seals;
• Its hydrophilic nature is essential in order to minimize dead spaces and to maintain films of water on surfaces that must be wetted to function properly;
• Its non-porous, impermeable surface does not harbor contamination;
• It is extraordinarily durable; and
• Its transparency permits visual inspection of internal components.
  
  

For discussions of this important issue, see Reagent Water and Water Purification Technologies in Perspective under the Position Papers > Issues Q/A and Articles > Review Articles menu buttons on the Lab Water References page.)

* See A Critique of ASTM International Standard D1193, Standard Specification for Reagent Water under the ASTM > D1193 menu button on the Lab Water Standards page.

** See AH/LabWater-1 under the Ad Hoc menu button on the Lab Water Standards page.