How To Install A Roots IMC/W2 Micro Corrector (2024)

/ / Roots

Is it easy to do?

Yes. We’ve received many questions in our company history as a Roots Dresser distributor on: “How do I install the IMCW2 Micro Corrector Head?” In this (hopefully short) post, we’ll walk you through the steps to install the IMCW2 Head.

What are the benefits?

The IMC/W2 Micro Corrector is the only version of a Dresser Roots Gas Meter that accurately measures BOTH pressure and temperature compensation. Other versions such as the standard CTR (Counter), are unaware of line pressure or temperature changes and offer only non-compensated readings. What’s more is by purchasing the Windows USB User Terminal Software and the IMC to PC Programming Cable you can have access to many extra features such as changing any parameters, view datalogs, inspect alarms etc.).

For reference, a 5 PSIG line pressure will throw off your reading by one-third. When gas is compressed more of it will flow through the meter. So for a gas meter with a base rating of 3000 cubic feet with a 5 PSI line pressure, the maximum flow rate is capable of 3,941 CFH using a pressure correction factor of 1.317. This is why pressure correction is so important with billing efficiency.

Where can I purchase one?

You didn’t think we’d offer a step by step tutorial without showing you where to buy one, did you? Of course we sell both the Conduit Version and the Circular Version from our Online Store, along with all the other Accessories discussed in this guide.

Let’s go!

Alright, enough chatting about it – let’s get to work.

What’s included with the IMCW2 Micro Corrector?

As you can see from the image below, the kit comes with one Handbook, three M4 x 20 cup fixing adjustment screws (235748-1), four 3mm hex screws, four Stand-off Spacers, a 3mm hexagon wrench (Allen Key), one Calibration certificated, and the very important 4″  buna-a orange o-ring seal (013491-000).

How To Install

1. Preparation

This first steps are important. The configuration for the correct size meter should be setup and uploaded to the Micro Corrector. One thing to note is that every Micro Correct comes configured standard from the factory for a 3M175 B3 Series meter. If the meter size happens to be a 3M175, then you can skip this first step. However, if your meter is a different size model, then you will need to configure it accordingly. This is accomplished using the User Terminal Software (also known as MCUT), and the PC to IMC Programming Cable.

User Terminal Software

IMC/W2 User Terminal Software

IMC to PC Programming Cable

IMC to PC Programming Cable

Begin by installing the User Terminal Software onto your laptop or desktop. It’s important to note that the MCUT Software is only compatible with Windows Based Software (sorry Mac users). The software is a very lightweight program.

One special thing to note is that not all desktops or laptops have a serial port. This can be easily fixed but purchasing a USB to Serial 9-pin Adapter. You will also most likely need the Prolific driver as well. Some of the drivers that come with the cheap cables made in China are often difficult to work, so we strongly recommend Proflic. You can find a Windows XP / 7 / 8.1 / 10 Driver here. For Windows 10 users with the latest OS updates you can pick up a USB to Serial 9-pin Adapter.

Choosing a Meter Size


Notice how using this software we can configure the correct size meter to be installed. One of the amazing things about this program is how many extra features that are included. You can datalog and save to Excel spreadsheets, set alarms, adjust the desired pulse output, change your flow direction, switch metric from imperial, and other options that we won’t get into today.

Installing the Corrector Head

Shut off your gas line before

Unscrew the 4 hex screws of the Aluminum Counter Ring to remove the head from the meter you want to install the IMCW2 on. You will need a 5/32 Hex Key for this (see below).

CTR Counter Screws

After you’ve done that you can begin removing the three 3mm Screws on the instrument cup flange using the included Hex Key. A few years ago removing the Flange was an easy task, however these days removing the Flange may be a little difficult. We’ve found that using a flat head screwdriver to separate (carefully) can do the trick.

Removing The Screws

Confirm that the black O-ring on the mounting flange is in the first groove (outside) position. It’s rare that Dresser would make this mistake, but it’s still an important safety check.

Removing the Seal Plug

Using a 1/4 Inch Hex Wrench, remove the orange Pressure Seal Plug (P/N: 012261-005). This is where you will install the pressure transducer from the IMCW2 Micro Corrector into the meter later on.

Remove The Pressure Port

2. Installation

Lubricating and Installing the O-Ring

You want to make sure that you don’t forget to apply a coating of lubrication to the o-ring. We use a multi-purpose lithium grease from Mag 1, but this is interchangeable.

Lubricated O'Ring

O Ring Install

Warning: Do NOT forget to install the included rubber orange o-ring (013491-000)

Inserting the 3 Sensors

We use a 5/8 Wrench Head to tighten the internal pressure sensor into the bored hole that closely resembles its similar size. It’s important that you make sure the internal pressure sensor has a black o’ring; moreover, that you tighten the sensor securely into the meter – otherwise a gas leak will occur.

Afterwards, insert the internal thermocouple into the thermowell to the proper depth marked.

Finally, insert the Magnetic Pickup (061749-000) into the Magnet Well. There are 3 color-coated depths to insert based on which meter size. Do not push too hard, this can damage the Sensor. You may need to rotate it back and forth while inserting.

WARNING: When tightening the pressure sensor DO NOT twist the wires. Simply rotate the head unit accordingly until the pressure sensor has been tightened securely, THEN install the Thermocouple and Magnetic Pickup. Failing to do so will damage the circuit board inside the correct head and render the unit irreparable.

Wrench HeadInstall Ports

3. Finishing Up

In the final step you will place the IMC/W2 Micro Corrector Head onto the Cup Flange and tighten the three 3mm head screws. Torque the screws to 15-20 in-lbs.

One of the nice features of the IMC/W2-PTZ is the ability to rotate the display up or down. To do this just loosen the three Screws, rotate the display, and then re-tighten. Do NOT attempt to rotate the unit after mating it flush as you could break internal wiring.


That’s It!

Now that you know how to install the IMCW2, you can have peace of mind knowing that your readings will be accurately pressure and temperature compensated.

You can order the IMC/W2 Micro Corrector from our online store HERE.

If you have any questions feel free to leave a comment below. You can visit the official Dresser Utility Solutions website for additional information directly from the manufacturer. Also don’t forget to visit our website to check out more of our products.

11 Comments to “ How To Install A Roots IMC/W2 Micro Corrector (2024)”

  1. Andrew Tracey says :Reply

    I appreciate these instructions but I am still having trouble connecting to a roots meter with my computer. I am running Windows 10 on my laptop and using the MCUT software I have a serial to USB adaptor and still unable to connect to the meter. Any help is appreciated.

    1. PV Team says :Reply

      Hi Andrew, thanks for the feedback. In the MCUT Software there is a button under Configuration that says “UT Comms Settings”, click that and under “Direct” you should see the Com Port that it’s currently trying to connect to (example: COM3). If you know which communication port your USB is plugged into then change the com port to match it. You can find out which com port the USB is using by going to Control Panel > Device Manager > Com Ports. In Device Manager you may need to click View at the top and select “Show Hidden Devices”. You can also make sure you have the latest adapter drivers updated for your adapter cable as a last resort. I hope this helps!

  2. Jack Johns de Chavez says :Reply

    where can I get the programming software

    1. PV Team says :Reply

      As of 2019, Dresser replaced the User Terminal Software Disc with a USB Card. P/N: 057446-080

      We recommend using the USB software on Windows 10 machines or later.

  3. Marwan Al Obaidi says :Reply

    Thank you for your well-done explanation, but with today off-site monitoring it will be appreciated if you have a complete set of solutions to transfer the pulse and corrected volume with CAT 6 cable to IT switches. Any kind of a compact solution either software or hardware will be such a step forward.

    Marwan Al
    Metering Manager

  4. James Cameron LaClair says :Reply

    Which wires get connected to the TB1 Terminal from the Mag well?

    1. PV Team says :Reply

      Hi James,

      WHITE = W1
      RED = W2/REED

      Hope this helps!

  5. Joe says :Reply

    5M175 root Meter under 14 inch water column how many cfh is the out put same as 7 inches

    1. PV Team says :Reply

      Joe, generally with Inches W.C. we do not worry too much about the pressure correction. But for a quick reference, here’s what it could look like:

      0.25 PSI = 5,056 CFH max
      0.5 PSI = 5,115 CFH max
      1.0 PSI = 5,225 CFH max
      5.0 PSI = 6,585 CFH max

  6. Jim Holak says :Reply

    Hi PV Team! Is a Remote Display available for the IMCW2 Micro Corrector Head?

    1. Jason Haring says :Reply

      They do offer wall mount versions.

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