Pre Order Asthma and Allergy Course
Over 6 million Australians have asthma and/or allergies that are often affecting their lives on a daily basis. This can cause missed work and school days. Asthma currently has no cure but it can be a manageable health condition.
The professional cleaning industry is able to perform an important and valuable service for those suffering from asthma and allergies. Find out HOW with CARSI’s Asthma and Allergy Course!
Expand your business and services with an affordable new product out on the market!
Podcast Series: Professional Carpet Cleaners and Restorers Podcast
The Professional Carpet Cleaners and Restorers Podcast (PCCRP) is new in the industry discussing informative information without offering advice that could be construed to be misleading, discouraging, malicious, and outside our professional knowledge and experience.
Broadcasted every fortnight discussing topics for small to medium size companies.
This week we sit down and discuss the transformation of a business in a North QLD township,
With Gary Bethel previous owner of Bethel Carpet Cleaning.
How they were able to not only establish their carpet cleaning business in an area dominated by well-established and high-profile cleaning companies but become the dominant carpet cleaning company in less than 5 years.
Is this still possible today?
Can these type of advertising strategies be implemented the same way they were over 20+ years ago?
The answer is YES!
Not only can they be implemented, but it will be cheaper, easier, and 10 X more efficient.
We are speaking with Gary Bethel.
We discuss where the industry has come from and where we feel it is going today.
Latest Podcast will be available this Friday 11th September @ 5 pm AEST
This month’s articles
Even before the science of wood’s relationship with moisture was well-understood, woodworkers had to factor in how moisture would affect their materials. Fortunately, we understand well the hygroscopic properties of wood today. Thus, we have been able to use that knowledge to design wood moisture meters that can provide us with quantifiable data about a piece of wood’s moisture condition. As our collective understanding has advanced, the testing methods have evolved as well.
Today, there are two main types of hand-held wood moisture meters: pin and pinless. Each relies on different electrical properties that are impacted by the amount of moisture held in the wood being measured, which we will explore in detail later in this article. For now, it is enough to say that pin-type meters use two nail-like electrodes that get inserted into the wood and measure the current that flows between them. Pinless meters use sensor plates that lay flat on the wood’s surface and measure the behaviour of an electric wave they send through the wood.
Without getting into the science of each moisture meter type, the most apparent differences between them are what they do to the wood being measured, and how easy they are to use.
Pin meters leave holes in the wood being measured. This makes them useful for evaluating the moisture content of firewood or pieces of wood where leaving multiple holes will not negatively impact the structural integrity or aesthetics of the final product. In contrast, pinless meters do not leave any physical markers behind. They can only be used on flat wood and the entire plane of the sensor needs to maintain contact with the wood during a reading.
A slow pace of work measuring wood’s moisture content is another outcome of having to insert or hammer in pins when using a pin meter. Inserting the pins to the right depth, removing them, and ensuring the pins remain in good condition to take a reading takes time. Consequently, when having to assess the moisture condition of a large piece or large batch of wood, you have to invest a significant amount of time. The more likely scenario is that you will simply take fewer readings. One extends project timelines and costs, while the other means you will be making decisions with fewer data points guiding you. You can work much more efficiently with pinless meters since they require less physical effort to use and are not as vulnerable to physical damage as the pin electrodes.
But this is where we are today. Electric moisture meters have nearly a 100-year history. Interestingly, they also still rely on an even older method – oven drying – to validate their accuracy. To appreciate how hand-held wood moisture meters of today operate, it is worth digging into the evolution of the technology on which they rely.
Researchers first validated the idea that we could use the electrical properties of wood as a measure of its moisture content in the late 1920s. One of the first portable electric wood moisture meters that we find documentation for, is a “blinker-type” meter, in 1927. This meter had a neon lamp attached to a capacitor, which was in contact with the wood. The capacitor would absorb the charge running through the wood. When the capacitor was fully charged, the neon lamp would briefly light up. The faster the capacitor could recharge, the faster the lamp would blink.
How quickly the capacitor could recharge was a function of how much resistance was in the wood. Since moisture conducts electricity, the more moisture in the wood, the faster the capacitor would reach a full charge. If there were high resistance in the wood (i.e., low moisture), then the lamp would blink slowly.
Within the following ten years, a new type of electric moisture meter was developed: a vacuum tube meter. This meter used a vacuum tube voltmeter as part of a Wheatstone bridge circuit, which uses a resistor to measure against the wood being measured. The vacuum tube meter is the direct precursor to the resistance moisture meters used today.
By the mid-1940s, pin-type meters were commercially available. They worked (and still do) by measuring the flow of an electric current between probes inserted into the wood. Like the early blinker-type meter, the more the current traveled between probes was an indicator of lower moisture levels. Without the conductivity of high levels of moisture, the dry wood presented resistance that nearly eliminated the current’s flow. Some early pin meters used four probes. Modern pin type moisture meters require only two probes.
During this period when resistance meters were hitting the market, researchers were also exploring how dielectric properties could be used to measure moisture in the wood. Dielectric materials can transmit electric currents without being conductors themselves. This research ultimately resulted in two other types of wood moisture testing methods that work on two different dielectric principles.
Without diving too deeply into electrical engineering, these two types of dielectric meters used radio waves to measure moisture levels. The power-loss type of meter looks at how much electromagnetic energy is lost, which correlates to moisture levels. The capacitance moisture meter takes the opposite approach. It looks at how much electrical energy can be stored. What they have in common, on a practical level, is that neither requires pins to break through the wood’s surface.
Instead, they use sensor plates that emit a radio frequency through the wood. The Forest Products Laboratory (FPL) of the U.S. Department of Agriculture had developed a capacitance-type machine to measure wood moisture levels, but it was not commercially available. By this time, many manufacturers were selling pin-style moisture meters.
By the early 1960s, there was one common power-loss type moisture meter on the market. During this period, Delmer Wagner, the founder of Wagner Meters, was working as an electrician for a sawmill in Oregon. The mill used a large, unwieldy vacuum-tube in-line moisture detector. To build a moisture meter that was both smaller and easier to calibrate, Delmer designed the first-in-line moisture meter. This in-line moisture measurement system used transistors to measure moisture. Delmer eventually left the sawmill and, in 1965, founded Wagner Electronics (known today as Wagner Meters), which built in-line moisture meters for the lumber industry.
Nearly all handheld wood moisture meters on the market through the late 1980s were pin moisture meters. However, these new pinless moisture meters were still quite large, hard to calibrate, and too sensitive to ambient conditions. Consequently, the pin moisture meter market thrived, while there were very few pinless meters.
In the 1990s, Wagner Meters set out to develop a pinless wood moisture meter that resolved the shortcomings of the pinless meters then on being sold in the marketplace. Wagner Meters’ first line of hand-held pinless moisture meters had an improved circuitry using electromagnetic waves that resulted in more accurate moisture readings. Also, the circuitry was less sensitive to ambient and wood temperature. Wagner Meters was also able to reduce the size of the hand-held meter significantly from what was currently available on the market. Pinless meters from other manufacturers generally weighed at least 10 pounds. The original moisture meters were designed for sawmills, but Wagner Meters added one explicitly designed for woodworkers by the mid-1990s.
Many experts and amateurs alike across the country use moisture meters to test the moisture content (MC) of various materials and products.
In moisture testing instructions and “how-to” guides, you may come across the terms “Quantitative Moisture Readings” and “Qualitative Moisture Readings.” What do each of these terms mean, and why would you want to have a quantitative versus a qualitative moisture reading?
- A Quantitative Moisture Reading is a representation of the moisture content of a sample material which is achieved by using a moisture meter that is specifically calibrated for testing moisture in that material. Examples would be the moisture readings provided by a wood moisture meter when testing wood, or a drywall moisture meter when testing drywall.
- A Qualitative Moisture Reading is an estimated value using an arbitrary scale. A good example of a qualitative moisture reading would be the results given by a reference scale moisture meter. The actual number is just a rough approximation of moisture content that may not translate into a precise moisture content percentage.
The difference between quantitative moisture readings and qualitative ones can be boiled down to a difference in specificity. A quantitative reading is specific and represents an absolute measurement of moisture content in a given material. A qualitative reading is an estimate that can be useful for comparison—but is ultimately not precise enough for many professionals.
In the restoration industry, customers rely on restoration experts to eliminate all traces of excess moisture in the structure so that it becomes usable again. Whether the property being restored is a residential or commercial property, lingering traces of moisture can create hazards such as:
Mould Growth. The growth of black mould and other fungi in dark, damp places is not a danger that most people consider—until they start smelling musty odours and people with asthma and other respiratory conditions start to experience side effects of mould spore exposure, that is. If too much moisture is left in building materials following dry-out/tear-out efforts, then there is a risk of mould growing in the structure—creating respiratory health hazards.
Potential Structural Failures. Excess moisture in a structure can weaken certain building materials. For example, wood beams can rot, making them susceptible to breaking under a heavy load. Water can rust iron-rich metals, compromising the performance of carpentry nails and other metal objects used to keep the structure together.
Pest Infestations. Pockets of water hidden deep in wooden structural beams and in other building materials can attract pests such as termites, rodents, and cockroaches. These pests can spread disease and eat away at structural materials—causing potential harm to the structure’s occupants.
The worst pockets of moisture can usually be found using a reference moisture meter—a qualitative moisture reading. However, when there are materials that are only somewhat damp, it can be hard to call them one way or the other.
This can lead to the demolition/tear-out of salvageable materials, or less-than-complete tear-out efforts as moisture-compromised materials are not properly identified.
Another issue in restoration work is documenting the necessity of dry-out efforts. In many cases, the restoration pro’s ability to collect a timely payment for their services depends on the insurance company’s willingness to pay out a property damage claim. However, before making any payouts, the insurer will want to verify that the restoration work was necessary.
Of course, for a moisture meter reading to be truly quantitative instead of qualitative, it is necessary to ensure the meter’s accuracy for moisture testing.
Ensuring moisture meter accuracy has several components, including:
Choosing the Right Moisture Meter. To get quantitative moisture measurements, the moisture meter needs to be properly calibrated for the material it is being used on—a hay moisture meter will not produce accurate results in wood, and vice versa.
Maintaining the Moisture Meter. Maintenance plays a significant role in ensuring moisture meter accuracy. A meter with damaged pins/scanning plates, depleted batteries, and a degraded circuit board is not going to work at peak accuracy and efficiency. Taking care of your meter is critical for getting quantitative moisture measurements.
Checking the Meter’s Accuracy. Even a well-maintained moisture meter can lose calibration after years of use. So, periodically checking the moisture meter’s calibration using a moisture content standard (MCS) or built-in calibration check can be invaluable for verifying that the meter is providing accurate measurements.
The term “reference scale” is used for a moisture meter reading mode wherein the meter takes qualitative moisture readings as opposed to quantitative ones. These qualitative moisture readings are shown as a numerical value which the user can then use to estimate whether that material is “wet” or “dry.”
It is important to note that the numbers used in a reference scale are not indicative of a specific percentage of moisture content. Instead, measurements in the reference scale are used as a relative indication of how much moisture a material has in it.
For example, say you have two different moisture meters. One meter might have a reference mode setting that displays moisture values from 0–300, while the other one goes from 0–100. While it might be tempting to think of readings on the 0–100 reference scale meter as percent values, they are not. A reading of 12 on a 0–100 scale does not mean that the material has 12% MC; it just indicates that the moisture content is relatively low.
The primary use of the reference scale setting on a moisture meter is to give it utility beyond reading moisture in one kind of material. Using a reference moisture meter reading mode, you can get a general idea of the moisture content of many different materials that do not have a specific reading scale.
One of the best ways to use a reference scale meter is to take a reading from an unaffected, dry sample of material. Once you have a reading from the “dry” sample, you can use that data as the baseline for the reference scale readings you get for that material for the rest of the job.
For example, if your dry material (carpet, for example) reads 33 on a 0–100 scale, and another sample of the same type of material reads 56, then that second piece of material is at least slightly damp.
This process of sampling a dry material to compare the dry reading to other readings of the same material should be done for each material being tested, each time you are at a new job site. Also, if you are testing for moisture in both interior and exterior environments, take reference readings for materials in both areas. The reason for this is that different materials might reach their equilibrium moisture content at different levels depending on the humidity of the environment. The humidity may change slightly from one job site to the next, and more so from the interior to exterior environments.
Additionally, for restoration work, you may want to perform the reference reading daily, as the ambient humidity of a structure will change as dry out efforts progress.
Another way to use the reference scale is as a quick “wet or dry” indicator for materials. On some analog reference mode moisture meters, the display has a colour-coded indicator. For example;
Green. This colour indicates relatively low moisture.
Yellow. This colour indicates some moisture — enough that material may be at risk and needs to be tested with a dedicated meter or some other accurate method.
Red. This colour indicates very high moisture content — the item is waterlogged.
Although these are qualitative moisture readings rather than quantitative ones, when a meter response is extremely high, that is a good indication the material is moisture-compromised.
While most DIY projects probably will not require relative humidity (RH) testing, there may be occasions where knowing the ambient humidity conditions can be useful.
For example, you may want to perform relative humidity testing in your house after a water damage remediation company declares that they have completed their dry-out operations. High ambient humidity in a room could be an indication that there are still moisture-compromised materials in the area, and that dry-out operations are not complete.
There are other examples of times that you might want to use a thermo-hygrometer—also known as an RH meter—such as when you’re preparing to install hardwood flooring, checking your heating, ventilation, and air conditioning (HVAC) system, or when assessing mould risk in a basement. Whatever task you end up using your RH meter for, however, you probably want to make sure that the relative humidity readings you get are as accurate as possible.
Ensuring RH meter accuracy can be difficult, as relative humidity readings can be affected by several different factors, such as:
- The placement of the sensor.
- Contaminants on the sensor element.
- The temperature of the room being tested.
The first issue is easily controlled, and different RH meters will usually have placement tips included in the owner’s manual to help you avoid problems.
The second issue is one of maintenance and storage. To prevent this issue, avoid keeping your thermo-hygrometer’s sensor out when it is not in use, storing it in its case whenever possible. If an RH sensor does get too badly contaminated, you will need to replace it.
However, the third issue, the ambient temperature, is one that many DIY enthusiasts might miss when checking the accuracy of an RH meter.
Moisture Zones (MZ)
- Indicated by led lights – Green, yellow, red
- Moisture zones the meter will see
Wood Moisture Equivalent (WME)
- Meters are calibrated to wood
- Not moisture content, moisture equivalent
- Wood is a consistent product
- Even electrical connectivity between species
- Hygroscopic material
What wood would obtain if left in the proximity of another material;
If you had concrete reading 25%wme and you sat wood on top of that concrete. If the wood was reading 14%wme, then the moisture from the concrete will move into the timber and if left in that environment, the timber will decay.
Moisture moves from wet to dry to try to equalize and find equilibrium.
Pin Meter Readings (PMR)
- Measures the resistance between two pins
- Very repeatable
- Additional extensions available
Non-Invasive Readings (NIR)
- Average reading across ¾ inch (20mm) depth
- Or highest reading depending on the meter
- The conductance of the material / Relative frequency method (RF)
Relative Humidity (RH)
- Meters do not read below 7%
Infrared thermometer (IR)
- Calculates the difference between dew point and surface temperature
Thermal Imaging (Thermography)
- An additional tool which shows the difference in temperature by colour
Picked by Phill McGurk
- Jon Jones @Jonnybones
- Khabib Nurmagomedov @TeamKhabib
- Amanda Nunas @Amanda_Leoa
- Stipe Miocic @stipemiocic
- Kamaru Usman @USMAN84kg
- Valentina Shevchenko @BulletValentina
- Israel Adesanya @stylebender
- Weili Zhang zhangweilimma (Instagram)
- Petr Yan @PetrYanUFC
- Alexander Volkanovski @alexvolkanovski
*Photo Credit @UFC
Released this month
- Standard Operating Procedures Template
- Hiring Process
- Onboarding Process
- SOP for the Tramex ME5 Moisture Meter
- Marketing Video for the Asthma and Allergy Product/Service to use in your business
- How to apply for a police check?
- How to apply for a blue card?
- How to apply for a white card?
Coming up next month
- How to complete a JSEA
- How to complete SWMS
- Training Register Checklist
- Introduction to ATP Meters
- How to optimise your Facebook Business Page
- Training Process
- How to complete a Standard Operating Procedure
- Introduction to Moisture Meters — Training Video