Category Archives: Preventative Maintenance

Distilled or Deionized Water? What’s the Difference?

Regular water from the tap, though not unhealthy to consume, can cause a great deal of problems when used with highly sensitive lab equipment.  It is important to remove ionic impurities and minerals from water to achieve precise results in any testing, formulations, calibrations or cleaning.


Impurities found in water include suspended particles, colloidal particles, dissolved organic and inorganic solids, dissolved gases, microorganisms, viruses and DNA.


Two of the most common processes used to remove ionic impurities from water are distillation and deionization (DI).




Distillation purifies liquid by boiling it, capturing the steam and then condensing the vapors. The condensed vapors are then returned to their liquid state finishing the distillation process.  Solids and other contaminants, salt being the most important, remain in the original container with just pure water being reduced to vapor. It takes approximately five gallons of water to create one gallon of distilled water.





Deionization removes minerals and ions, both cations (positively charged ions) and anions (negatively charged ions), through a chemical process. DI uses specially manufactured ion-exchange resins which exchange hydrogen ions and hydroxide ions for dissolved minerals, which are then recombined to form water (this leaves DI in an unbalanced condition and with an electrical charge.)  DI does not significantly remove uncharged organic molecules, viruses or bacteria. Because deionized water is unbalanced, it goes after any dissolvable or absorbable ions on contact trying to return to a balanced state.


So how do you know whether you should use distilled or deionized water in an application?


Lab Uses


Because distilled water is pure, it’s valuable in research since it is a constant and does not interfere with any chemical processes. Distilled water is used primarily as a solvent for reagent preparation, as a calibration standard or analytical blank, for cleaning testing equipment and rinsing an analyte. Distilled water is used when making High Purity Water. It should be used in all equipment sterilization.


Deionized water is used when an application requires a soft solvent.  DI water works best in cooling applications because of its lack of mineral deposits. Deionized water is also used in reagent preparation, transferring an analyte within a test procedure, as a calibration standard or analytical blank, and for cleaning lab equipment. DI water is best for washing glassware because of the absence of minerals and ions.  DI is corrosive and should not be used when there will be extensive contact with certain metals.


As Drinking Water


Deionized water should never be consumed as drinking water since the deionized process does not remove bacteria or viruses (compared to municipally filtered drinking water.) The jury is still out about the benefits of drinking distilled water.


Can They Be Substituted?


Not always – distilled water can be substituted for deionized water, but deionized water should never be exchanged when distilled waster is called for in any application. Always check with the manufacturer’s instructions before speculating about whether distilled water or deionized water should be used. Your Biotechnical Services technician can always help you determine which one to use.

How to Improve your Lab’s Asset Utilization Ratio

The last thing you want to do today is to waste resources. With funding sources plummeting, every penny counts in the biotech industry. A major loss of revenue can come from an unexpected and calamitous equipment breakdown. For every second the equipment is offline, production and income are lost due to the instrument’s and the employee’s downtime.

What is Asset Utilization?

12711647579wa7j7Asset utilization, or fixed asset turnover, is an important ratio for every lab manager to know. Asset utilization indicates if your lab instrument is being used to its full potential and efficiency. Asset utilization monitors your equipment’s performance to help increase sales revenue and/or improve productivity. Simply stated, the higher the ratio, the more efficient the management of the lab instruments and the greater the sales and output potential   – though there are circumstances when a high ratio can be deceiving.

Depreciated Value

Lab equipment, unless rented or leased, is considered one of your organization’s fixed assets, along with property and buildings. Over time lab equipment depreciates in value. In the eyes of the IRS, the expected life for lab equipment is 10 years.  So determining the realistic expected life time of your lab equipment is needed to figure out the asset utilization ratio.

Asset Utilization Ratio AKA Fixed Asset Turnover Ratio

The fixed asset turnover ratio is expressed as:

Fixed-asset turnover = net sales / average net fixed assets

Your net sales could also be your net production levels or net funding accrued.  The average net fixed assets are the cost of the fixed asset less their depreciated value.

What you are determining is: for every dollar spent on fixed assets, how much revenue am I earning OR how productive am I?

A high ratio tells you that your fixed assets are working efficiently.  As mentioned above, a ratio that is too high may also indicate that your equipment is too old and past its depreciated value life span.

How to Improve Your Asset Utilization Ratio

Improving your asset utilization ratio can be achieved with a number of different ways:

  • Replace equipment past its useful life — Know the expected life of each unit
  • Maintain your instruments in proper working order — Take care of small problems so they don’t become big ones
  • Schedule regular maintenance — Preventative maintenance ensures fewer breakdowns
  • Know the piece of equipment’s efficiency level — What should be the output?
  • Regularly test for efficiencies — Schedule your testing on the calendar
  • Record all testing results – Keep good records
  • Compare testing results over set time periods — Can alert you to any issues with a change in efficiencies

Maintaining the highest efficiencies of your lab through the close monitoring of your asset utilization ratio will contribute to both your bottom line and production levels.

Increasing Your Lab ROI with Preventative Maintenance

Lab Equipment Preventative Maintenance

Has your lab decided to cut operating costs in the coming year? Is one of the line items preventative maintenance (PM) for your lab equipment?

If increasing your return on investment (ROI) is also on your business plan, you should actually increase the amount spent on PM.

In 2000, Jones Lang LaSalle[1] conducted a study attempting to assess the value of PM programs and the subsequent ROI. Their results? An investment in PM not only pays for itself but also produces a huge return on investment.

Determining the Financial Model

The study established a baseline of between 4.5 percent and 7.5 percent of annual operating costs was spent on repair and maintenance of equipment.

A statistical model was developed to not only quantify ROI but also to quantify the net present value (NPV) of investing in preventative maintenance.

Their research focused on 15 pieces of equipment looking at the following factors:

  • Type of equipment
  • Amount of equipment
  • Size of equipment
  • Age of equipment
  • Annual preventative maintenance expenditures for equipment

To determine the value of PM, the study attempted to quantify the following:

  • Actual cost of preventative maintenance
  • Cost of repair/corrective maintenance
  • Cost of replacing equipment
  • Expected useful life of equipment expected useful life of equipment
  • Effects of preventative maintenance on expected useful life
  • Frequency of required repairs when equipment is not maintained
  • Effect of PM on energy consumption

Preventative Maintenance Scenarios

Three PM scenarios were considered:

  1. No preventative maintenance – the company spends zero on preventative maintenance for any of its equipment.
  2. Current preventative maintenance levels – the actual amount spent on PM at the time of the study.
  3. Industry benchmark PM – spending the industry benchmark amount on PM for each specific piece of equipment.

For each scenario, the researchers calculated the yearly cost of operating a piece of equipment and built in a timeline of expenditures. The operating cost consisted of energy, repair maintenance, preventative maintenance and replacement cost.

The average life of each piece of equipment was used to determine when the equipment would need to be replaced. All expenditures were brought back to present value for each piece of equipment.

The Results of the Study

The analysis indicated an NPV of $2 billion over 25 years for a $39 million per year preventative maintenance program. This boils down to an ROI of 545 percent.

The French proverb, “penny wise and pound foolish”, describes preventative maintenance. Proper maintenance adds years to the expected useful life of a piece of equipment and avoids spending expensive capital for a replacement. The longer the capital expense can be delayed, the higher the ROI will be.

Finding the right PM plan to fit your needs can be time-consuming. BTS has three different Preventative Maintenance programs – choose the one that’s right for you and your ROI. Plan now to save costs next year – and for years to come.

Biotechnical Services, Inc. – We Bring Life to Research


[1] Koo, Wei-Lin and Tracy Van Hoy P.E.  (2000) Determining the Economic Value of Preventative Maintenance: Jones Lang LaSalle