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Catalog & Brochures

Full Product Catalog
2016 Full Product Catalog


Product Brochures
Oil And Gas
2016 Oil and Gas Brochure


Water and Wastewater
2015 Water and Watewater Brochure


Datasheets & Manuals

Level Transmitters
Ultrasonic Sensors
LOE Tank Cloud Master Sensor

datasheet | user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual

DST Sensors


Submersible Pressure Transducers

Continuous Float Level Transmitters
MPX Magnetostrictive Sensor


user manual

installation guide

RP Resistive Chain

datasheet | user manual

RPM Explosion Proof Resistive Chain

datasheet | user manual

Remote Monitoring
Tank Cloud Compatible
LOE Master Sensor

datasheet | user manual

RST-5003 Master Module


user manual

installation guide

PT-400 Pressure Transducer

datasheet | user manual

MND Modbus Display

datasheet | user manual

Controllers and Displays
Modbus Displays

4-20 mA Displays


datasheet | user manual

Pressure Sensors
Pressure Transducers

datasheet | user manual

1502 Hammer Union Pressure Tansmitter


user manual

installation guide

2202 Hammer Union Pressure Tansmitter


user manual

installation guide

Digital Pressure Gauges

Level Switches
Float Switches
Kari Cable Suspended

datasheet | user manual

FT-100 / FT-300 Cable Suspended

datasheet | user manual

MLS Movable Float

datasheet | user manual

Level Switches
NLS Pneumatic

datasheet | user manual

PWS Paddle Wheel

datasheet | user manual

VBL Vibrating Switch

datasheet | user manual

Discontinued Products

datasheet | user manual


datasheet | user manual

AGV-1000 Collision Avoidance

user manual

Pressure Gauges & Equipment
PC-10K Comparator

user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual


datasheet | user manual

RST-5000 Master Module

datasheet | user manual

Other Sensors
TLS Cable Suspended

datasheet | user manual



Software Downloads

Modbus Sensors
Ultrasonic Sensors
Continuous Level Transmitters
Pressure Transducers

How long is your warranty?

We have a standard 2 year warranty on our products. This covers "defects in materials and workmanship under normal use and service". We stand by our products and our customers, and will repair or replace items as fast as we can. Please see our full warranty statement on our Terms & Conditions page.

What do I need to do to send my unit back for evaluation?

Contact us and ask for our tech support. Our tech support engineers will gather some information and, if they are unable to help troubleshoot your problem, they will issue you an RMA number via email. You'll also receive the necessary shipping information. That's it! We try to make it as easy as possible to get the service you need.

Do I need a Return Material Authorization (RMA) number?

Yes. All returns need an RMA so they can be tracked. If we didn't have an RMA number, we wouldn't be able to serve you as effectively. With it, however, we can ensure a smooth process and give you the treatment you deserve.

Is there an evaluation fee?

For products under warranty, when there is a warranty repair needed, there are no fees or repair costs. We do, however, charge an evaluation fee of $50.00 for products that are NOT under warranty, or for products that have no defects in material or workmanship. The warranty covers "defects in materials and workmanship under normal use and service." If a repair is needed, but it's not due to defects in material or workmanship, then the $50.00 evaluation fee would apply. If a unit is sent in and no repairs are needed, we have to charge the evaluation fee to cover our costs.

However, if you have to pay the $50 fee, it will count towards the repairs costs. The goal isn't to charge you extra money, but to prevent a business loss due to erroneous warranty claims.

Do I still pay an evaluation fee if my unit is not repairable?

If your unit is unrepairable and you want APG to scrap the unit for you, we will waive the evaluation fee. The evaluation fee would apply, however, if you need your unrepairable item returned so we can cover the cost of additional handling.

Do I pay an evaluation fee if nothing wrong is found with my unit?

We have to charge the $50 evaluation fee for warranty claims when nothing is wrong. We do this simply to offset the cost of providing this valuable service. In order to avoid this fee, we recommend working with our tech support to ensure that your unit is in need of service before you send it in for repairs.

When do I pay the evaluation fee?

If required, we'll arrange for payment when we give you the results of the evaluation. If repairs are required and you choose to proceed, we can bill you for the repairs and the evaluation at the same time.

How fast can you fix my unit?

That depends on what repairs are needed. Once we receive your unit, we'll evaluate it within a few business days and contact you with a lead time.

How much does it cost to repair my unit?

Once the evaluation is completed, you'll be contacted and given all the details to either repair or replace your unit. Final costs will be given for your approval. The $50 evaluation fee (mentioned above) will apply toward the final cost of the repairs.

Why do I have to pay to ship my unit back to you when it is under warranty?

We require you to cover the cost of shipping your unit back to us as it has not yet been evaluated. Once we receive your unit and can verify that it is indeed under warranty, we will repair it and ship it back to you at no additional cost.

In this case, "under warranty" means that it needs repairs due to a defect in material or workmanship for normal use and service. That just means that we have to find something wrong with the unit, and that you cannot use our sensors for applications outside of their design. To give you an example of a use beyond the scope of the design, we wouldn't cover water damage on a sensor lacking the proper IP and/or NEMA ratings.

Can I use a Class 1 Div 1 sensor in a Class 1 Div 2 area?

Yes. The difference between Div 1 and Div 2 is all about the constancy of the threat of explosion. If it's constant, or common, it's Div 1. If it's possible, but not common, it's Div 2. Therefore, a Div 1 rated sensor is safe in all Div 2 areas.

What's the difference between Explosion Proof and Intrinsically Safe?

Explosion proof is a method of containing sparks within a small housing, and allowing the expanding gasses escape into the atmosphere only once they are cooled. This keeps the spark from turning into a fire or explosion. The wiring to support this method is quite involved and expensive as everything has to go through sealed conduit. This protection method is necessary for high powered devices such as pumps.

Intrinsic safety prevents sparks, fires, and explosions by never allowing enough current in the electronics to cause a spark or generate heat. The sensors are designed to operate on this low current, and an electrical barrier is placed between the sensor and the power source to control the current and eliminate surges and spikes. This protection method is safer and typically less expensive to wire.

When do I need to use an Intrinsically Safe barrier?

An Intrinsically Safe (IS) barrier is needed to maintain IS wiring. One is needed for every conductor wire that goes into an IS installation. They're needed for IS sensors and for any simple apparatus, such as a float switch.

What's the difference between Divisions and Zones?

Divisions and Zones are the result of two methods to express similar ideas. They each describe the constancy of the hazardous mixture in a hazardous area. Divisions are used in the US, and divide hazards into two categories:

  • Div 1 is an area where the threat of fire or explosion is possible under normal operating circumstances. This includes normal maintenance and repair operations.
  • Div 2 is an area where the threat is only possible under abnormal circumstances, like equipment failure.

Zones are used in Canada, Europe, and many other places. This method divides hazards into three categories:

  • Zone 0 describes a constant threat under normal circumstances.
  • Zone 1 describes an intermittent threat under normal circumstances.
  • Zone 2 is an area where the threat is only possible under abnormal circumstances.

Do you offer NIST certificates?

Yes. We offer NIST certificates for our pressure products. On certain pressure ranges, we can offer a NIST certificate for accuracies up to 0.1% FS.

Do you offer calibration services?

Yes. We can calibrate anything we make. Contact us via phone, email, or live chat to discuss your calibration needs and to get a quote.

How often should calibrate my pressure sensors/pressure gauges?

The answer to this question depends largely on your expectations for accuracy. Many quality departments have an adequate calibration schedule that we can safely defer to. However, as we expect a high degree of accuracy, we recommend a calibration once per year.

Can you calibrate my unit to a higher accuracy?

We can calibrate pressure sensors and gauges to a higher accuracy than our standard option if it falls within select pressure ranges. Most pressure ranges above 100 psi and below 10,000 psi are capable of accuracies up to 0.1%. If you haven't already had us calibrate to that level of accuracy, we can still get you there.

Is there a quick way to calibrate my sensor in the field?

Most of our sensors can be programmed in the field. This includes setting your minimum (zero) and maximum (span) set points. Let's break it down a little for you:

  • Ultrasonic sensors are all field programmable. In this process, you'll set your min and max set points as desired. You can redo this process as needed.
  • Continuous float level transmitters are not field programmable. They leave our facility already calibrated, and this should last the life of the sensor.
  • Our submersible pressure transducers are even capable of some quick field calibration. You can re-zero the sensor using a magnet.
  • Digital pressure gauges are also fully programmable. You can set the zero and span on each gauge.
  • Our pressure transmitters, except for our hammer union pressure transducer, also have a zero and span adjustment.

Calibration is really done for pressure sensors. Our level sensors don't experience drift over time like a pressure sensor will. Send your pressure sensor back in for calibration on a regular basis, at least once per year, to ensure the best accuracy possible.

How can I get a good level reading in turbulent liquids?

Turbulence is a tricky challenge that may require a few extra steps. For ultrasonic sensors and continuous float level transmitters alike, you can install a stilling well. This is a tube that extends from the sensor mount to the bottom of the liquid. A hole is drilled at the top of the tube that allows air to escape and the liquid to rise up the tube at the same level as the main body of liquid. While the liquid in the tube is the same level, it is buffered from any turbulence - hence the name "stilling" well.

Another good way to do this is to use a submersible pressure transducer. While they're not a good solution for a blending tank, they are unaffected by turbulence at the surface.

Will your sensors work in extreme heat or cold?

Most of our sensors operate somewhere within the -40° to 180° F window. However, some of our float switches are capable of working in heat up to 392° F. If you need a sensor in temperatures close to it's limitations, there are still a few options. In hotter temperatures, you may be able to use a stand pipe or a heat sink to cool hot temperatures just enough before they reach the sensor to allow accurate measurement. In colder climates, you may need to install the sensor inside of a box or a housing with a heater installed.

Do you have sensors that work with caustic chemicals?

Chemical compatibility must always be verified before you purchase a sensor. This is incredibly important to ensure safety. That said, we do have sensors that can work in caustic chemicals. The materials we use for our sensors include 316L Stainless Steel, PVC, and Nickel Alloys. Just make sure you check chemical compatibility. If you're unsure, give us a call and we'll check for you.

What's the best way to measure an interface between two immiscible liquids?

Making interface level measurements are tricky. This is often considered one of the most difficult liquid level measurements out there. And we're proud to have a very reliable solution. Our MPX continuous float level transmitter uses magnetostrictive technology to detect a float that sits right at the interface of the two liquids. It simultaneously detect the float at the top as well, so you can get both a total level and an interface level on the same sensor. It can even provide a temperature reading. This probe is used extensively in the oil and gas fields where oil and water are stored in the same tank.

How can I measure level in a pressurized tank?

In lightly pressurized tanks, you can use a standard sensor - as long as the pressure in the tank does not exceed the rating of the threads. For our ultrasonic sensors, that's only about 30 psi. However, if you have a lot of pressure inside a tank, or highly variable pressure, you should use differential pressure. This is done by measuring the liquid column with a pressure sensor at the bottom, and measuring the gas pressure with a sensor at the top. You simply subtract the gas pressure from the liquid pressure, and you'll be able to calculate a level.

What's the difference between pressure range and pressure ratings?

Pressure range is the range within which a pressure sensor can accurately measure. Pressure rating refers to the physical limitations of a sensor's process connection. For example, a 1502 wing union connection can hold at 10,000 psi, but it's not rated for 15,000 psi. So we can calibrate our 1502 Hammer Union Pressure Transmitter to 15k psi, but we do so with a warning - the fitting isn't designed for that pressure range. This is incredibly important. Don't confuse the pressure range of the sensor for the pressure ratings of the fitting. If you do, you might end up with a projectile, or even an explosion.

How do I know which pressure type I need?

If you want the right pressure type, you need to understand what they are, how they measure, and why they're used. There are five pressure types:

  • Gauge
  • Compound
  • Vacuum
  • Sealed
  • Absolute

Gauge pressure measures everything above atmospheric pressure. It considers the pressure of the atmosphere as zero pressure - just like you do. This is widely used, and definitely the most popular type amongst the pressure sensors we sell.

Compound measures above atmospheric and below atmospheric - all the way to vacuum. This pressure type is useful when you need to see positive and negative pressure. However, there are usually good reasons to use the Absolute pressure type instead (see below).

Vacuum pressure measures from atmospheric pressure to vacuum. It's only measuring the vacuum. This is useful when you want to compare a negative pressure to atmosphere.

Sealed pressure uses the atmospheric pressure at the time it was sealed as it's zero point. This comes with it's own set of difficulties at lower pressure ranges. But it's great for higher pressure where the minute differences in atmospheric pressure don't matter.

Absolute pressure is also sealed, but under a full vacuum. It's zero point is true, or absolute, zero. Even vacuum pressures are seen as positive pressure to the absolute pressure sensor. This is often a better choice than compound because your reference point is fixed. It's also the basis of many calculations, such as head and resistance calculations in pump systems. Using an absolute pressure gauge on your pumps reduces the conversions needed to make use of your measurements.

To know which type you should use, you need to understand your goals. You should also understand what types of conversions you would have to do once you have a measurement. It's also hepful to know that sealed pressure sensors are better for dusty or moist environments. In many cases, you would do yourself some good to use an Absolute pressure sensor as long as you know how to interpret it properly.

If the explanations above aren't helping you, please contact us so we can discuss your application and get the right sensor.

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