MODEL 2200-3000 RETROFIT OPEN STREAM CURRENT METER / PAGE 4 OF 7
Supplement to Model 3000 Instruction Manual
to the photo-sensitive transistor. If the fiber-optics or the LED and transistor are allowed to get too
dirty, light transmission will be impeded. Periodically check the fiber optic rotor
(2200-A14)
and
wash the ends of the optics in clear water. Soap and water may be used if surfaces are very dirty. Do
the same for the LED and Photo-Transistor in the Sensor body. CAUTION: Do not scratch the
surfaces of the LED and Photo-Transistor.
2. Regularly clean out and re-lubricate (use same type oil as originally supplied with your meters) the
inside of the sensor adapter chamber where the rotor turns and also check for bearing wear between the
chamber and the upper rotor shaft. If side to side play is excessive rotate the Adapter ¼ turn and
check side play again. Replace the Adapters (
2200-A1
, Pygmy &
2200-A2
, AA) if play is excessive
or vibrations occur which cannot be corrected by adjustments or lubrication.
APPLYING CALIBRATION CORRECTIONS TO THE MODEL 2200-3000
The default Calibration Numbers (Props 4 and 5) for the Model 2200-3000 are for the "Velocity" reading and
"Disch Modes" only and are for USGS Price Meters which are "standard rated" (Prop 4 is the AA meter and
Prop 5 is the Pygmy meter). Damage to the bucketwheel cups, maladjustments and excessive bearing wear
will influence this rating as will meters not produced to U.S. Geological Survey specifications.
It is possible, using the Model 2200-3000, to change the calibration and compensate for some types of damage
to a Price Type meter and still obtain accurate velocity data. It must be recognized however, that any damage
to a meter other than minimal bucketwheel cup damage (bent or dented slightly) should NOT BE
COMPENSATED FOR. The meter itself should be reconditioned with new parts and re-rated in the normal
manner before use with the Model 3000 Indicator.
See the Model 3000 Indicator operating instructions for further information on calibration and calibration
corrections.
AA METER RETROFIT PROBLEMS
1. In
some
AA Yokes it has been found that a deep chamfer has been made in the hole through the top of
the Yoke. The chamfer has no effect on the original Catwhisker contactor's fit but it can
seriously
effect the positioning of the Swoffer adapter
. If the chamfer is deep enough it can allow the
2200-A2
adapter to drop too low around the
2200-A4
shaft and cause clearance problems between the
Adapter, the Shaft, the Fiber-Optics Rotor
(2200-A14)
, and the Sensor
(2200-A)
.
The threaded
portion of the adapter must not drop below the top level of the AA yoke
.
2. Swoffer has produced special tapered washers for some customers with incorrectly machined yokes but
it is impossible to predict in advance the amount of any yoke's chamfer since
a chamfer is
not called
out on USGS drawings
. The chamfer is entirely at the discretion of the machinist.
If you do have an excessive chamfer in your Yoke you can hold the Adapter in the correct position (the
bottom of the threaded section of the Adapter exactly even with the top flat surface of the AA Yoke)
while tightening the set screw on the front of the Yoke. If the set screw is kept snug then operation
without a shimming washer can be very satisfactory.
PYGMY METER RETROFIT PROBLEMS
In some Pygmy (mini) meters the holes through the upper and lower yokes are not concentric. This
condition does not effect the original catwhisker operation so these meters may have been in the field
for years operating without problems.
But
a non-concentric condition will seriously affect the fit and
function of the Fiber-Optic rotor when installation is attempted on an out-of-tolerance Pygmy yoke.
While installing, if the fiber-optics rotor contacts the inside of the Adapter anywhere during rotation
then immediately and carefully remove the kit parts entirely. The Pygmy yoke must then be adjusted
or replaced before re-installation of the fiber optic sensor adapter kit is attempted. Call Swoffer
Instruments, Inc for help in this regard. (206) 575-0160.
