Levels Explained

Wednesday, 20 April 2011 01:19

Written by Nicholas Papp

Each discipline specifies several other criteria for each Type (i.e., I, II, III, or IV). Needless to say, the three disciplines do not agree on exactly what constitutes each type.

For practical purposes:

Type I ultrapure water usually means water that has 18 Megohm-cm or greater specific resistance, with other attributes such as bacterial count, TOC (total organic carbon), pyrogen and/or endotoxin and/or R-Nase and/or D-Nase levels, and specific ionic contaminant levels usually specified by the end user. It is essentially a given that this water meets the other criteria specified by CAP, ASTM and NCCLS.
Type II water usually means water that has 1-2 Megohm-cm or greater specific resistance, with other attributes such as bacterial count, usually specified by the end user. It is essentially a given that this water meets the other criteria specified by CAP, ASTM and NCCLS.
Type III water, per the CAP and NCCLS, means water that has 0.1 Megohm-cm or greater specific resistance, while ASTM defines it as having 4 Megohm-cm or greater specific resistance!
Type IV water is only defined by ASTM, as having 0.2 Megohm-cm or greater specific resistance.

Last modified on Thursday, 07 March 2013 01:34

Read 2302 times

Published in Water Filtration

Social sharing

Nicholas Papp

Nicholas Papp has a B.S. in Physics, with Minors in Chemistry and Math, from Baldwin-Wallace College. He is the Vice President and General Manager of Aqua Solutions Inc., and has worked in the water filtration/purification industry for more than 35 years.

Latest from Nicholas Papp

More in this category: « Tips on Buying a Lab Water Purification System Deionization Filtration »

From Our Blog

Tips on Buying a Lab Water Purification System
Buying tips that can help you get the best system for your money! 1.Silence is golden - but make sure the system runs 24/7. Noise does not purify water! The Type I System you buy should have a pump that… more details
Do you require UV filtration in your lab water system and what type?
Water is one of the most commonly used reagents in the laboratory. It is an indispensable solvent for many uses like for preparation of buffers, media, liquid phases, gels and many more. Before water can be used in the laboratory… more details

Aqua Solution News

Nano pore technology makes cost effective water production
The Arcada University of Applied Sciences in Helsinki successfully produces nano-sized pores to cut water production costs. Dr. Mikael Paronen, head of the Department of Energy and Materials Technology, claims that this nano pore technology could be globally significant in… more details
Rochester Waste Management to address wastewater treatment issues with RO system
The Turnkey Landfill of Rochester under the city's Waste Management will be using a reverse osmosis (RO) system to address the wastewater treatment plant problems, including the low transmissivity levels in the water as well as the significant amount of… more details