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For companies with busy and cramped product lines, there is always a drive to improve their technology. By using better, more efficient equipment, manufacturers can keep up with increasing demands and improve conditions inside their facility. At Big Bear Instruments, we offer a selection of Unitronics terminals and programmable logic controllers (PLC). These high-quality products are among the most sought-after pieces of equipment in the industry.

An All-in-One PLC with HMI
With a compact, all-in-one integrated operator interface, this product provides the benefits of a single operating panel and PLC controller with less wiring needed. Unitronics PLCs feature an integrated Human-Machine Interface (HMI) with easy-to-understand and use digital screens.
Four Major Product Lines
Companies can pick and choose from a diverse selection of PLC product lines. Each offers features dedicated to meeting specific needs from the simple and traditional industrial i/o to cutting-edge customized designs. Our PLCs are also available with a wide variety of screen sizes and capabilities.
Faster, More Powerful Software
Included with your equipment, at no extra charge, is an all-in-one programming environment and utilities suite. Configure communication and hardware, and Ladder and HMI applications inside of intuitive, easy to understand software. Unitronics has also developed software to support IoT and Industry 4.0 applications.
We at Big Bear Instruments are pleased to be a provider of Unitronics products.  For more information, please contact us. One of our knowledgeable representatives will be happy to schedule a free consultation with our experts.

Manufacturers have to keep track of many elements during production or, even, to just maintain their facilities. Sensors are the devices that make it possible to keep track of everything remotely, efficiently, and to automatically make adjustments based on the data gathered. Big Bear Instruments strives to provide industrial and manufacturing companies with the well-made level control and flow sensors they need to remain effective and productive. Our selection of Gems sensors are useful in many industries from food to medicine to HVAC.

The Selection of Superior Sensors

Have you ever purchased a low pressure gauge and noticed the pointer was pointing off of zero? You probably thought your gauge was broken and needed to be replaced.  This is a very common issue for people who are using liquid filled pressure gauges on their applications. Reason being, glycerin naturally expands and contracts due to temperature changes so whether the gauge is sitting on a warehouse shelf, in a shipment, or outside for a while, small buildup of pressure can happen inside the case of the gauge causing the very sensitive bourdon tube to push the needle off of zero. The good news is your gauge is not broken. There is actually a very quick fix for this issue - it's called “burping” your pressure gauge.
For a visual tutorial, we think Kodiak Controls explains it best with their YouTube video titled “How to Burp a Pressure Gauge."

If you do not have video access right now, grab a flat head screw driver and follow these steps below:

1. Take your flat head screw driver and place it carefully near the fill plug on the top of your gauge.
2. Gently push the fill plug to the side to alleviate some of the air.
3. Be careful not to push the fill plug all the way in. If this happens and you can’t get it out, you’re probably going to have to buy a new gauge.

Air or glycerin may come out during this process or the fill plug may fall out entirely. All of these things are OK! Just make sure to put the fill plug back on carefully so that it doesn’t get pushed inside the gauge (see step 3).

If done properly, your gauge should now be pointing back at zero. If you are still having issues or have any questions, please contact us! Our team of technical experts would love to help.

A pressure gauge out of calibration can be extremely frustrating for any industry. For microbrewing, a gauge out of calibration can literally offset the entire regulator system which controls the CO2 levels for the brew.  Depending on the severity of the offset, the gauge could be pointing off of zero when there’s no pressure in the line or the gauge could potentially read 1-5% above or below the range it should really be reading. This can become quite an issue for beer brewers because the consistency of the beer depends on an accurate PSI reading.  Without a precise reading, the beer could be foamy or flat and let’s be honest, nobody wants that.

To avoid dealing with an inaccurate pressure reading on the line, we suggest getting your gauges NIST certified yearly to keep up with calibration standards.  If you don’t want to go through process of sending out your gauges for this certification, we suggest calibrating them yourself in house with an already NIST certified digital gauge. Both of these processes will leave you with a certified, accurate, well working pressure gauge that keeps your CO2 regulators reading accurately.

For those of you who don’t know what a NIST traceable certificate of calibration is, let’s take a moment to fill you in. A NIST certificate is a document stating the pressure instrument falls within the accuracy stated by the manufacturer. It is approved by The National Institute of Standards and Technology (NIST) because the pressure instrument is tested against another, more accurate, NIST traceable pressure instrument. The NIST certificate is essentially a way to get 100% certainty by NIST standards that the pressure instruments you’re using falls within specification.

Now let’s take a deeper dive into the two ways we suggest getting your pressure gauge certified:

Sending Out Your Pressure Gauges for NIST Certification:

One way to be sure the pressure gauges on your CO2 regulators are accurate is to send out your current gauges for calibration. Big Bear Instruments performs NIST Certificates of Calibration daily for many of our customers and we offer expedited 1 day turnaround if you're in a hurry. We test your pressure instrument against our NIST traceable digital gauge at 5 points (or more if requested) spanning the entire scale of the pressure instrument in question. So, for instance, on a 0-1000 psi digital gauge, the gauge would be tested at 200psi, 400psi, 600psi, 800psi, and 1000psi. The reading of the pressure instrument must fall within the accuracy range stated by its manufacturer when tested against our NIST traceable pressure gauge.

Calibrating Your Pressure Gauges In House:

If you are looking for a more inexpensive way to calibrate your pressure gauges, you can purchase an already calibrated digital pressure gauge and perform the calibration process in house using a DIY process specialized for brewers.  Depending on your desired accuracy, Big Bear offers the MG-9V, MGA-9V, and MG1-9V series digital pressure gauges manufactured by SSI Technologies. All three models are battery operated and can be NIST Certified by us prior to being shipped to you. If you are not sure which model is right for you, feel free to contact us.  We would be happy to walk you through the benefits of each model and help you select the best gauge for your brewery.
If you have any questions regarding calibration or want to know what kind of beer is our favorite, contact us! We’d love to hear from you.
 
 

So you’ve figured out what size dial and connection you need on the gauge for your application. You even know your preference on wetted materials. But what about having the gauge dry vs. liquid filled? What are the benefits to a liquid filled gauge? Are there any negatives? Believe it or not, determining this feature can be puzzling for many customers.  Be confused no more – Big Bear will explain everything you need to know about why a gauge is liquid filled.
To put it simply, liquid filling a pressure gauge is strictly used as an inexpensive way to steady the needle and lubricate the internals of a gauge during applications with vibration. The most common fill fluids used are Glycerin and Silicone. Glycerin is used in around 95% of all liquid filling applications and is typically the “standard.” The reason these fluids are used is because they’re more viscous and their thickness helps keep the needle steady. Some gauges come dry but can be filled simply by filling the hermetically sealed gauge case through the fill port (usually at the top) and then reinserting the fill plug when finished.
As with any decision making, you should outweigh your pros and cons when deciding what’s right for you. Let’s break that down for you here:
Benefits of a Liquid Filled Gauge

• It steadies the needle. Without liquid filling the gauge, the needle would bounce erratically making it difficult to pinpoint where the needle is exactly pointing on the gauge
• It’s an inexpensive solution and in many cases comes standard on a gauge
• It helps increase the life of the gauges by dampening as well as lubricating the mechanical parts of a pressure gauge

Negatives of a Liquid Filled Gauge

• Discoloration (darkening or yellowing) of glycerin over time due to exposure of UV rays or extreme temperature changes
• Standard Glycerin is really only good down to 20 degrees Fahrenheit. It is not recommended for cold environments
• Risk of leakage
• Pressure can build up in the case due to expansion and contraction of fluid from temperature changes (usually small, 1 PSI or so) affecting the accuracy of the reading as well as bring the needle off of zero

While some of these negatives can seem like deal breakers, there are easy solutions to these issues. We’ll start with discoloration. If potential discoloration is a concern, instead of choosing Glycerin, go with Silicone. Silicone has a bigger temperature tolerance and is not as easily affected by UV rays.  Because of this, Silicone tends to keep its color longer than Glycerin.

If your application has very low temperatures of 0 degrees or below, Silicone or a mixture of Glycerin and distilled water can be used instead of pure Glycerin. Both of these fluids will allow for lower temperatures down to -40 degrees Fahrenheit.

As for leakage, this is always a risk with liquid filled gauges but the risk is very low.  The chance of leakage depends on the quality of the gauge you’re using as well as the application. If your main concern is leakage, to decrease risk, use a crimped bezel type instead of a bayonet due to the crimped bezel holding the gasket in place permanently and is less likely to come loose in the field or by human error. Again, the risk of leakage is low nowadays due to improvements in manufacturing technologies and standards.

Last but not least, let’s talk about pressure build up. Pressure build up inside a gauge can happen and is very natural for a liquid filled gauge. The pressure build up (usually very minimal) can sometimes cause the needle to move off of zero and/or cause the gauge to read inaccurately + or – 2-4%.  To alleviate the pressure, burp the gauge by slightly lifting the fill plug. Once done, you’ll see the needle move back to zero.  If you’ve never done this before, we recommend watching Kodiak Controls' short video for a step by step guide on how to burp a pressure gauge.

If you have any further questions or would like help in finding what pressure gauge is right for you, contact us and our trusted staff will be happy assist.

A pressure gauge out of calibration can be extremely frustrating.  The gauge may constantly point off of zero when there’s no pressure in the line or the gauge is consistently reading 5% above or below the range it really should be reading based on your other instrumentation.

One solution to this problem is to utilize the adjustable pointer on the pressure gauge assuming your gauge has one.

Most industrial pressure gauges will have an adjustable pointer because gauges will commonly fall out of calibration out in the field due to vibration, pulses, or just general use.  Gauges that don’t typically have them are smaller utility pressure gauges or liquid filled gauges.  Usually they’re lower in cost and its cheaper just to replace than try and worry about adjustments.

Below is a link to a video by our friends at Kodiak Controls explaining how to adjust the calibration of a pressure gauge using an adjustable pointer.  Keep in mind that an adjustable pointer can only help if the needle is off by 1-10% of the full range.  So, if you have a 100 psi gauge and the needle is always off by 3 psi, an adjustable pointer will work great.  But, if your 100 psi gauge is off by 30 psi, an adjustable pointer is not your solution.  There is a bigger issue at hand and you may need to purchase a new pressure gauge.  Enjoy the video!

How to Use an Adjustable Pointer

Digital pressure gauges have been around for decades, but until recently, they have become more relevant in industrial, laboratories, and testing applications than ever before.   So, why the change?
Here are a few reasons why digital pressure gauge usage has surged.
1.) Cost – The cost of digital gauges has dropped dramatically over the last 5-7 years.  In the past, one might expect to pay around $300-$400 for a standard digital gauge with basic features.  At that price, it didn’t really merit switching from mechanical gauges that could be purchased around $20.  However, now due to technology and more efficient production, digital gauges can be purchased as low as $125 for high accuracy units or as a low as $15 for a real basic digital gauge.
2.) Availability – With costs being lower and usage going up, many digital gauges are being stocked in standard configurations instead of being made-to-order.  This allows customers to have easier access and quicker deliveries on these products.
3.) Point-of-Reference Display – Its much easier to get an accurate reading by looking at a digital display instead of an analog dial.  Think about looking at a mechanical clock vs. a digital clock.  The reading is clear and concise.  There is no “fudge factor” in the reading.
4.) Special Features – Digital pressure gauges can also come with additional features like:

•  4/20mA outputs
• numerous scale readings
• max and min readings
• data logging
• no moving parts = more durability than mechanical gauges

5.) They’re Better  – Digital pressure gauges are overall just flat out better than mechanical gauges.  They’re more accurate in most cases, readings are easier to get, 4/20mA outputs are available, and digital gauges are more durable.
One thing is for sure, digital gauges aren’t going anywhere anytime soon.
For more information on digital gauges, visit our digital pressure gauge page or contact us.

At Big Bear Instruments, we're strive to provide great products at great prices. One of the products we'd like to highlight this week is a mini digital pressure gauge manufactured by Kodiak Controls.
Kodiak’s new KCDG15 digital gauge is perfect for reading pneumatic pressure applications where higher accuracy, better durability, and clearer readability is needed over a standard analog mechanical pressure gauge.  The KCDG15 digital gauge is designed to be a better overall pressure gauge and provide a more reliable reading while still keeping the price much lower than a traditional digital gauge.
The KCDG15 is battery operated and can come in 1/8″ npt or 1/4″ npt threaded connections (other options available at request) and is 0-145 psi standard (other ranges also available).  It is battery operated and has a 1.0% F.S. accuracy with LCD display.
For additional details or to purchase this mini digital gauge, check out the product page.

On high vibration industrial applications, reading a pressure gauge can often be frustrating or in some cases down right impossible without the proper configuration on the gauge.  Very often, the end user may experience:

• The indicating needle shaking back forth making it difficult to get an actual reading
• The indicating falling off its access from the vibration
• Damage or short longevity of the gauge due to constant wear and tear of the pressure gauge internals

There are a few options that can be used to help legibility of the pressure gauge:

1. Liquid Filling – Liquid filling the gauge with either a glycerin or silicone is easily the most popular solution and least expensive.  The viscosity of glycerin or silicone makes it a thicker fluid than something water.  With the case filled with glycerin, the needle has a harder time from shaking back forth from the vibration.  This in turn steadies the needle and allows for accurate reading.  In addition to help steady the needle, the glycerin also acts as a lubricant for the internals of the pressure gauge allowing for a longer life out in the field.
2. Dampening Movement – Getting a pressure gauge with a dampening movement is the next best option especially for those who do not like liquid filling and prefer a dry gauge.  A silicone dampener is put on the internals of the pressure gauge near the axis of the pointer.  This steadies the pointer and allows for the same outcome as if the gauge was liquid filled.  Typically a dampening movement needs to be special requested though
3. Capillary Tubing with Diaphragm Seal – As an option for extreme vibrating applications where liquid filling and/or dampening movements aren’t enough, the pressure gauge is often mounted to a capillary tube and diaphragm seal filled system.  The diaphragm seal is mounted at the process connection.  Capillary tubing (often 5 feet in length) is connected to the diaphragm seal and on the other end of the tubing is the pressure gauge.  The pressure gauge is then typically mounted to a wall or panel away from the vibration and a proper reading can be seen.  The diaphragm seal, capillary, and gauge assembly is filled with a fluid (often silicone), to allow for an accurate reading.

For a complete list of our liquid filled gauge options, take a look at our mechanical gauges product page.

For differential pressure applications with caustic or thick medias, mounting a differential pressure gauge directly to the process can be detrimental to the integrity of the gauge.  The wetted material of the gauge may corrode away or the differential gauge could potentially become clogged.

A solution to this problem would be to isolate the wetted parts of a differential gauge by mounting diaphragm seals made of a compatible metal or plastic to the inlet and outlet sides of the differential gauge.  However, unlike a standard pressure gauge with one port, you cannot mount a diaphragm seal directly to the differential gauge because the ports of the gauge are typically too close together to accommodate the size of the diaphragm seal.

A solution to this is to install capillary tubing in between the gauge and the diaphragm seal.  This allows for flexibility during installation, safety from high temperatures or vibration, and room for the diaphragm seals to fit on the gauge.  The entire assembly is a filled system just like a standard gauge mounted on a diaphragm seal.  The air is evacuated from the assembly and replaced with a fluid (usually silicone or glycerin).
For more information on differential gauges and/or mounting instruments to diaphragm seals, contact us.

A pressure instrument by itself typically has a small orifice for the media to enter into it for measurement.  This works perfectly fine for applications such as water, air, or oil measurements.  But what do you do if the media has solids in it, is thick, and/or solidifies when it cools that can potentially clog the pressure instrument rendering it useless?
The answer is mount a diaphragm seal to the instruments.  A diaphragm seal is specifically designed to be a barrier between the media and the pressure instrument.  Pressure gauges, pressure transducers, and pressure switches can all be mounted to diaphragm seals (or gauge isolators as they’re sometimes called) through a “filling process” creating a sealed system between the instrument and the seal allowing for the utmost accuracy.
There are many kinds of diaphragm seals and all are used based on what fits best for the application.  Some types include:

• Mini Diaphragm Seals
• Large Diaphragm Seals
• Plastic Diaphragm Seals
• Flow-Through Diaphragm Seals

IMPORTANT: You cannot simply screw on a diaphragm seal to a pressure instrument.  As mentioned above, it needs to be a filled system.  Essentially the instrument is mounted to the diaphragm seal.  Then air is evacuated from inside the connection and replaced with a fill fluid such as glycerin, mineral oil, or silicone.  This allows for an accurate reading.
For more information on diaphragm seals or the mounting process, please contact us.