Inclinometer monitoring programs often run several years or more. During this time, hundreds of surveys can be collected. Each new survey is processed by comparing it to a baseline survey.

Over a period of years, normal wear and tear can gradually degrade the probe’s ability to produce new surveys that are directly comparable to the baseline survey. This may go unnoticed for some time, because the quality of readings may degrade in very small increments.

When function tests are incorporated into an inclinometer monitoring program, the degradation of reading quality can be avoided. Probes that pass the tests can be used with confidence. Probes that fail the tests should be returned to the probe manufacturer for servicing. It should be noted that manufacturers calibrate inclinometer probes using high-precision, electronically-controlled equipment in temperature-controlled environments. Ordinary users do not have access to such equipment, so the pass/fail criteria suggested for these tests accommodate typical results produced by less precise equipment in a less controlled environment.

The quality of the result produced by this standard is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.

1.1 This practice describes three function tests that together can be used to verify that a vertical inclinometer probe is working properly.

1.2 This practice does not address calibration routines, electronic diagnostics, or repair of the probe, nor does it address inspection of the probes mechanical parts.

1.3 This practice is not intended to replace manufacturers recommendations for servicing and calibration of inclinometer equipment, nor is it intended to replace maintenance and calibration schedules established by users as part of their quality programs.

1.4 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a projects many unique aspects. The word "standard" in the title of this document means only that the document has been approved through the ASTM consensus process.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.