Figure 1. C17 Digital Inclinometer System

1. Introduction

At Soil Instruments we recommend a yearly calibration of our Inclinometer systems to ensure they are working to the highest accuracy possible. However, if you feel that your Inclinometer requires a calibration every 6 months due to heavy use it is possible to check the values you are receiving compared to your original calibration values. To do this you will need the Inclinometer Calibration Certificate from the previous calibration as well as a way to accurately cycle the probe through its measurement range in accordance to the Calibration Certificate.

2. Checking calibration values

The readings you receive on your field PC screen will correspond to the readings that can be seen on the Calibration Certificate (see figure 2.) at each angle. These will have been adjusted if any adjustments were required from the latest factory calibration from its original calibration.

Figure 2. Example Inclinometer calibration certificate

A method of checking whether your Inclinometer has drifted since its last calibration is by using a Soil Instruments Reference Frame (catalogue code C10-3.8). If you do not have a reference frame and would be interested in purchasing one please either contact sales for a quote or let us at the support centre know and we shall forward on your request. This allows the user to systematically cycle through three positions (-10deg, 0deg, +10deg) corresponding to your Calibration Certificate, to which the readings on the field PC screen either will correspond or will not correspond depending on whether the calibration is still valid. 

If you do not have a Reference Frame you will require a piece of equipment to enable you to accurately cycle through the degrees stated on the certificate. You will then need to set up a test borehole on the field PC with 7 depths to check the Inclinometer readings at each position, starting at -30 degrees and ending at +30 degrees (See figure 3.). Once you have set up the test borehole please turn the inclinometer on and allow the unit to warm up/stabilise and take the readings at each position. Once you have taken the A0 readings please remove the Inclinometer and rotate it 180 degrees to take the A180 readings. Whilst taking the A180 readings if the 'Face Error' message appears the unit may be outside its recommended tolerance and may require re-calibrating. Please then complete the same steps for the B axis.

Figure 3. Cycling the probe through the angles

If after testing the Inclinometer you feel it requires returning for calibration, please submit a ticket to the support site requesting a service case number for the Inclinometer, alternatively you may call Soil Instruments on +44 01825 765044 for advice.

Checked MO'R v1.0 13/05/15