Calibrate the pressure sensor on a Field Gauge and Process Meter

Do-it-yourself instructions for calibrating a Ralston digital gauge with the free FieldLab Desktop software. At the end of this process, FieldLab Desktop will automatically make any necessary adjustments to bring your Ralston gauge to acceptable tolerances.

This article applies to the following devices:

1. Process Meter LC20, all models.
   
2. Field Gauge LC 10 and LC20, all models equipped with one or more pressure sensors.

Things you will need:

1. A PC running Windows.
   
2. FieldLab Desktop software version 1.38.0 (or later) installed on your PC. Download the latest version for free.
   
3. A Ralston Instruments digital gauge.
   
4. USB Cord, provided with your Ralston gauge.
   
5. A pressure source that can generate enough pressure to take the Ralston gauge to full span.
   
6. A reference pressure gauge with the following:
   
1. Reference gauge should be 4 times more accurate than the Ralston gauge you are calibrating.
   
2. Reference gauge must have a full span equal to or greater than the full span of the Ralston gauge.
   

1. Connect the Ralston gauge and reference gauge to the same pressure source.

2. Power on the Ralston gauge.

3. Connect Ralston gauge with the provided USB cord to a PC running FieldLab Desktop.

Download the latest version of FieldLab Desktop for free.

4. In FieldLab Desktop on your PC, select the Ralston gauge you want to calibrate from the Devices screen.

5. On the gauge Overview screen, select the tab titled "Sensors".

Select the tab titled Sensors

6. On the Sensors screen, select the button titled "Calibration".

7. Select the pressure engineering units you want to use for the calibration process.

Note: The example screens in this support article were taken from a Ralston gauge model with a full span of 300 psi.

Ralston gauges are available with full spans from 30 to 10,000 psi; so when you are calibrating your Ralston gauge be sure to follow the actual Min, Mid, and Max calibration points displayed on your computer screen in FieldLab desktop.

8. Adjust the pressure source to the target pressure.

FieldLab Desktop display the live pressure reading from the Ralston gauge via the USB connection. FieldLab Desktop cannot see the reading on the reference device, so you will need to adjust the pressure so that the reference device displays each target pressure.

If you can't get the reference device to read exactly the target pressure get it as close as you can and then manually enter the reference device reading into the Reference Reading field using your keyboard.

9. When the reading on the reference device indicates you have reached the target pressure, select the "Log Reading" button.

10. Select the button titled “Up Next, Mid Point” to proceed to the next reference point.

Repeat steps 8, 9, and 10 above for each of the remaining reference points.

11. Once you have logged the Min, Mid, and Max Points, select the Make Adjustments button.

After you select the Make Adjustments button, FieldLab Desktop will recalibrate the Ralston gauge if it is out of spec.

Select the Make Adjustments button once you have logged the Min, Mid, and Max points.

12. Set the Next Calibration Date

13. Save Changes so that the next calibration date will be recorded on your Ralston gauge and in FieldLab Desktop.

14. Select Exit to return to the overview screen for your Ralston gauge.

• Related Articles

• Installation instructions for panel-mounting a Process Meter LC30

  1. Cut holes in panel using diagram 2. Position LC30 over holes 3. Insert bolts from front and install nuts loosely in back 4. Tighten nut until snug, but not too tight 5. Connect pressure / temperature connections 6. Connect power via approved power ...

• Quick-Start Guide and User Manual for Field Gauge LC10

  Download in PDF format below.

• Toggle sensor reading displayed on screen with a two-sensor Field Gauge LC20 and Process Meter LC30

  1 Each sensor on a dual-sensor gauge will have a laser-etched label (A and B). The Field Gauge and Process Meter screen displays the readings for one sensor at a time. To change which sensor is being displayed, tap the Menu / Up Arrow button.

• Overview Video Field Gauge LC20

  Field Gauge LC20 basic operation and features overview.

• Replace Batteries in a Field Gauge LC20

  Power off the gauge. Remove the four screws from the back of the gauge with a 2mm hex key/Allen wrench or Phillips-head screwdriver. Older models shipped with hexagonal sockets, newer models ship with Phillips-head screws. Remove the back panel. ...

• Recent Articles

• How to Place an Order Using the Ralston Instruments Distributor Portal

  Purpose: This article explains how Ralston Instruments distributors can efficiently place an order using the Ralston Instruments Distributor Portal. Note that this is only available to users who are employees of authorized Ralston Instruments ...

• How to Request a Quote from Ralston Instruments

  Overview At Ralston Instruments, we aim to make the quote request process as streamlined as possible for both end users and distributors. This guide outlines the steps for each group to request a quote efficiently. For End Users End users are ...

• Calibrate the pressure sensor on a Field Gauge and Process Meter

  Do-it-yourself instructions for calibrating a Ralston digital gauge with the free FieldLab Desktop software. At the end of this process, FieldLab Desktop will automatically make any necessary adjustments to bring your Ralston gauge to acceptable ...

• How long do the keypads on the LC gauge last?

  The keypad buttons on the LC10, LC20 and LC30 gauges last typically 5-10 million cycles. This varies depending on the ambient temperature as well as the force with which the buttons are pushed.

• How National Pipe Thread (NPT) works

  NPT (National Pipe Tapered) threads are a standard used in the U.S. for connecting pipes and fittings. They are designed with a taper meaning that as you screw the male thread into the female thread, the diameter decreases and the threads become ...