Please excuse us while we work on improving our website.If you have any questions, or would like to contact us about our services, Please contact
Terry Clausing, P.E. CEA
Email terryc@virtualspectrum.com
Ph 513 739-2317


Devon Clausing
Email devonc@virtualspectrum.com
Ph 513 739-0354


General information
Drysdale & Associates, Inc
PO Box 44055
Cincinnati, OH 45244
Email drysdale@virtualspectrum.com
Ph 513 831-9625

Drysdale & Associates, Inc.

50 Years of Ingenuity

Founded by George H Drysdale in 1964, we have over 40 years of experience in infrared temperature measurement sensors as well as vacuum measurement, mass flow of gases and a variety of related process variables. Over the years we have gained a great deal of knowledge in spectral analysis, so rather than simply selling infrared temperature sensors, we are experts in the field of ultraviolet (UV), visible (VIS) and infrared (NIR and IR) spectral and thermal infrared analysis. We use the term “spectral analysis” because there is much information contained that is valuable to monitoring manufacturing processes, and temperature is only one of the spectral variables. For example, the NIR region can provide excellent process moisture measurements for materials from food processes to paper processes. The NIR region also lends itself to a great number of other process constituents as well.Our expertise in infrared temperature measurement has led us to establish our own infrared instrumentation calibration laboratory, and our customers have led us to seek ISO 17025 accredidation (certification in process). Beginning in 2008, we offer infrared temperature calibration services for all manufacturers of infrared temperature sensors and infrared cameras. Our laboratory services guarantee one week turnaround, and we offer ON-SITE INFRARED CALIBRATION SERVICE where we bring our laboratory blackbodies to your site and perform the calibrations in your facility. Our senior calibration specialist is a licensed professional engineer and is ASNT Level III Certified in infrared non-destructive testing methods. MORE THAN INSTRUMENT CALIBRATION: All infrared temperature sensors require an emissivity setting. Although your instrument may be properly calibrated, if the emissivity is not set correctly, the instrument will read the wrong temperature. Users of infrared thermometers struggle with ensuring that their infrared temperature sensors are reporting the correct temperature for their process. Drysdale & Associates, Inc now offers on-site temperature calibration for your process! We are uniquely qualified to certify that your process is operating at the correct temperature. Mr. Terry Clausing is a certified expert in nondestructive thermal and infrared testing: ASNT Certified NDT Level III T/IR and a licensed Professional Engineer.   We have extensive expertise in moisture monitoring and control for manufacturing processes. Moisture is often measured by infrared spectral analysis. We are happy to assist you with all of your infrared and thermal spectral analysis requirements.

Why “VirtualSpectrum”?

Drysdale & Associates, Inc provides a range of products and services that covers a wide spectrum, and these products and services tend to be spectrally related. Infrared temperature led us to infrared cameras and moisture analysis in processes. The infrared cameras led us to energy and moisture analysis in industrial and commercial structures.

All of this led us to understanding Building Science in order to empower homeowners to understand energy use in homes.  Today, we have partnered with BPI to help educate home owners to significantly improve the energy efficiency of their homes – this project is most exciting because the result improves the comfort of the homeowner in their home AND reduces their cost to live in their home at the same time.

Introducing Drysdale Energy 

In April of 2010, Drysdale & Associates, Inc became a BPI Affiliate and training provider. Back around 1998, we were very busy selling infrared cameras when I met Don Jones and Paul Remilspaul in a HERS rater class for weatherization. Don and Paul were ahead of their time, as they were already using infrared cameras in their energy audits of houses. Infrared cameras at that time typically cost anywhere between $20,000 – $50,000 so very few weatherization people could afford the equipment. Don, now deceased, and I became a good friend and I applied much of my HERS training towards commercial and industrial energy audits and worked together on complex projects such as inspecting the Taft Museum prior to its renovation.

EnergyStar® is primarily a certification for new home construction. In more recent years there is increasing recognition of the need to improve the energy efficiency of our existing houses. The greatest problem we have as homeowners is the trying to figure out truth from fiction from all the companies that are trying to sell us their miraculous energy saving windows/furnaces/insulation/geothermal/whatever. When you walk through a home and garden show, you come out with the impression that if you bought all hype, you would save so much money that your utility company would be paying you if you did it all. So how is a homeowner supposed to make good informed decisions? That is the issue, and I hope to provide you with the answers here. The answer begins with knowledge. The following quotation is attributed to Benjamin Franklin:

               “Tell me and I forget.

               Teach me and I remember.  

               Involve me and I learn.”

Drysdale & Associates, Inc training is dedicated to the teachings of Franklin and our training begins with homeowner training. My own greatest realization over the last 30 years since graduating from high school, is that the more I have learned, the more I have realized that there is yet to learn. The second greatest realization has been that simply because something is normal, that does not make it right. Normal is whatever circumstance we live with every day. If we want a better life, we need to choose to do things differently and make different choices. Einstein is credited with saying that the definition of insanity is to do the same thing again and again, and expect a different result. We, our society, have spent the last 50+ years learning to take energy for granted and to waste energy. The solution to our energy problems has little to do with developing solar or whatever alternative energy source you want to discuss. Rather it has everything to do with understanding how we use the energy we have and learning to use it more efficiently.

In most cases our utility companies are for-profit companies. If you ask them how to become more energy efficient, their first recommendation is to set your thermostat back and make yourself colder in the winter and hotter in the summer. These utility companies desire for you to believe that reducing energy means that you must be uncomfortable. Their second recommendation is usually even billing, to make it less painful to continue giving them more money.

The fact is that energy efficiency is about living MORE COMFORTABLY, keeping more of your money in your pocket to spend on the things you want instead of giving it to the utility. And when energy efficiency is done properly, it also results in a healthier, more durable home – and lower utility bills.

Homeowner knowledge begins with a professional home energy audit. BPI, the Building Performance Institute, trains professionals to provide genuine information to homeowners. As you shop for a person or company to analyze your house, you need to ensure that they are qualified to provide the information you will need. BPI accredited residential energy auditors provide this service. Professionals are also people, and there are always some who do a better job and some who do a lesser job. You need to ensure that the professional you choose, does a professional job for you.

A professional BPI energy audit will require typically 2-3 hours or more on-site and will include the following:

1.     An interview with you to discuss any problems or concerns you have regarding your house

2.     An exterior analysis of the property

3.     A comprehensive examination of your HVAC and DHW systems, including combustion appliance zone testing if you have combustion appliances.

4.     A blower door test to measure the leakiness of the structure

5.     An infrared examination to determine insulation issues and air infiltration issues

6.     An evaluation of the attic, basement, crawl space and discussion with you regarding establishing the proper thermal and pressure boundary for your home.

7.     An examination of your base-load appliances such as refrigerators, freezers, and lighting.

8.     Most importantly, a PRIORITIZED LIST OF SPECIFIC RECOMMENDATIONS to help you choose the best measures to improve your energy efficiency and make your house more comfortable.

Your BPI accredited energy auditor should have received comprehensive training. The following is primarily for those of you who are reading this information and seeing the tremendous potential for becoming involved.

BPI Building Analyst course

Drysdale & Associates, Inc offers the BPI Building Analyst course:  This is a 5 day course to prepare you for the Building Analyst on-line and field examinations. Both examinations are included in the course fee of $1,895. per person, as well as a copy of the text, Residential Energy. Class size is limited to 12 persons.

The Building Analyst requires high school math skills. Basic knowledge of residential construction techniques is also very beneficial. You are expected to be familiar with balloon frame construction vs platform framing, and you are expected to be comfortable working around all construction materials such as fiberglass, cellulous, 2-part polyurethane foam, and crawling around attics and crawl spaces.

The course is very intensive. The course time is 50% classroom, 50% field work learning testing techniques in actual houses, and 50% homework. You should expect at least 3 hours of homework each night. ALL EQUIPMENT IS PROVIDED (blower door, combustion analysis, combustible gas detector, Infrared Camera, etc). You will need to provide a calculator, flashlight, and work-appropriate clothing.

BPI Envelope Specialist course

Drysdale & Associates, Inc offers the BPI Building Analyst course:  This is a 5 day course to prepare you for the Envelope Specialist on-line and field examinations. Both examinations are included in the course fee of $1,895. per person, as well as a copy of the texts, The Building Shell Field Guide (Saturn Publishing) and the Thermal Bypass Checklist Guide (USEPA). Class size is limited to 12 persons.

The Building Analyst certification is a prerequisite for the BPI Envelope course. The Envelope course requires a deeper capability of math and science and is especially directed towards people who are performing energy related house improvements.

This course focuses on deeper diagnostics, including training and use of the IR camera for insulation and air infiltration diagnosis. While the IR is not part of the BPI Envelope requirement, it is essential in performance of the actual work. Testing will include pre-and post- testing with demonstration of the importance of 2-part polyurethane foam in establishing the thermal and pressure boundaries.

The course is very intensive. The course time is 50% classroom, 50% field work learning testing techniques in actual houses, and 50% homework. You should expect at least 3 hours of homework each night. ALL EQUIPMENT IS PROVIDED (blower door, duct blaster, combustion analysis, combustible gas detector, Infrared Camera, etc). You will need to provide a calculator, flashlight, and work-appropriate clothing.

BPI Building Analyst for HERS raters

Drysdale & Associates, Inc offers a two day course specifically for HERS raters. This course covers combustion safety and the essential elements of the Building Analyst requirements. This two-day course includes the BPI Building Analyst on-line exam and field exam. The cost for HERS raters is $995.

IR Camera Training for Building Science Applications

Drysdale & Associates, Inc offers a two courses. The first is a 2-day introduction to Infrared Thermography for Building Science Applications: This course covers the basic operation of infrared cameras and teaches their use in accordance with the RESNET IR standard and the USEPA Thermal Bypass Checklist Guide. This is a general introductory class and does not meet the RESNET or ASNT Level I requirements for infrared thermography. The cost is $895. per person. All equipment is provided and you do not need to own an infrared camera.

The second infrared course is our ASNT Level I Infrared Thermography for Building Science: This is a 4 day course to prepare you for the RESNET infrared camera training requirements. This course includes a 40 question ASNT compliant Level I examination in infrared thermography for building science applications, and practical field exam. The course is $1,695. per person.

Most of our classes are conducted for companies who desire to become BPI Gold Star Contractors or those who are actively involved in various aspects of the energy efficiency. Our classes are typically taught at your facility. We also provide classes for colleges, universities and utilities.

The courses are taught by L. Terry Clausing, PE. Mr. Clausing is a BPI Certified Proctor and Trainer, and a HERS rater. In addition, he is an ASNT Certified Level III expert in infrared and thermal non-destructive testing. Mr. Clausing chairs the ASTM committee E07.10 on infrared non-destructive testing and serves on the Board of Directors for the American Society for Non-destructive Testing.