Maintenance Schedule; Calibration Items; Maintenance Items - Teledyne WORKHORSE Operation Manual

WorkHorse H-ADCP Operation Manual

Maintenance Schedule

To ensure that you continue to receive optimal results from your Teledyne RD Instruments product(s),
TRDI recommends that every H-ADCP be returned to our factory for an inspection every two to three
years. We'll provide your unit with a thorough multi-point inspection, and let you know if any refurbish-
ment services are required to properly maintain the unit. To learn more about this service, please
field service.

Calibration Items

Use the following calibration schedule:
Item
Transducer Beam Angle
Pitch & Roll (Tilt)
Temperature (Factory)
Pressure Sensor (Factory)
Heading (Field Pre-Deploy)
Heading (Field Post-Deploy)
Pressure sensor and compass drift effects will accumulate over time. TRDI recommends a
factory calibration be done every two to three years. The longer you wait between factory
calibrations, the more error (due to drift) you can expect to have.
For example, the pressure sensor has an initial accuracy spec of ±0.25%, and a long-term drift
spec of ±0.11%. Most of the 0.11% drift will occur in the first 12 months of operation. The
fluxgate compasses accumulate an error of approximately 1% over a year.

Maintenance Items

Inspect the H-ADCP to spot problems:
Item
Transducer Beams
O-rings
Housing and End Cap
TRDI Recommended Period
TRDI recommends returning the H-ADCP every two to three years for verification of velocity accuracy
TRDI recommends returning the H-ADCP every two to three years for Factory calibration
Field Compass Calibration (AF) performed prior to each deployment (see
Field Compass Verification (AX) performed post each deployment (see
TRDI Recommended Period
The urethane coating is important to H-ADCP watertight integrity. Many users are not familiar with the early
signs of urethane failure. The primary damage to the urethane is from bio-fouling and long exposure to the
water and sun. Damage occurs on the surface of the urethane and at the edge where the urethane bonds to
the cups. Mishandling, chemicals, abrasive cleaners and excessive depth pressures can also damage the trans-
ducer ceramics or urethane coating.
Before each deployment, check the urethane coating on the transducer faces for dents, chipping, peeling,
urethane shrinkage, hairline cracks and damage that may affect watertight integrity or transducer operation
(see Figure 20).
Based on experience, TRDI knows that most systems need to have the urethane inspected after three to five
years of field use; shorter periods may be required depending on marine growth.
O-rings should be replaced whenever the system is opened and BEFORE they are showing any signs of wear
and tear. Replace the end-cap O-ring each time the end-cap is removed.
All O-rings should be replaced every one to two years maximum.
Inspect for damage and replace as needed before each deployment.
Inspect the paint on the end-cap, housing, and transducer assemblies for corrosion, scratches, cracks, abra-
sions, paint blisters, exposed metal (silver-colored aluminum), exposed anodize (black or dark green), and
exposed primer (yellow). Be critical in your judgment; the useful life of the H-ADCP depends on it.
tective Coating Inspection and Repair
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Compass Calibration
for details.
May 2015
contact
Compass Calibration)
Verification)
See Pro-
Page 45