Set Screw Bio-wiper™ Service

Some ECO models are available with an anti-fouling bio-wiper™. The bio-wiper™ extends the possible deployment duration by retarding biological growth on the instrument's optical surface. The bio-wiper™ covers the optical surface:
while the instrument is in “sleep” mode;
when it has completed the number of samples requested;
when the user selects Stop Data in ECOView (or types “!!!!!” in a terminal program).
When the meter wakes up, the optical surface is exposed by the bio-wiper's™ counter-clockwise rotation.

If power is shut off in mid cycle, the bio-wiper™ will reinitialize to the beginning of the user-selected settings when power is applied again.

The bio-wiper™ can be removed by using the factory-supplied 0.050 hex key to loosen the set screw that attaches the wiper to the instrument. Take care to ensure no unnecessary torque is placed on the shaft.

To clean, wash in soapy water, rinse and dry thoroughly. Note the condition of the copper on the instrument side of the wiper. It is normal for the copper bio-wiper™ to corrode and turn green, especially after the instrument has been removed from the water. This corrosion will slightly reduce the wiper's antifouling ability the next time it is deployed.

For maximum antifouling capability:
Remove bio-wiper™
Buff with a pad of green Scotch Brite^® (or similar) until shiny
Re-install bio-wiper™

To re-install the bio-wiper™ on the instrument, the wiper blade must be properly flexed. To achieve the proper flex of the wiper, set the gap between the copper bio-wiper™ and the instrument face to 0.03 in. (0.8 mm). An improperly set gap will either fail to clean the face, or cause the motor to draw excessive current.

Not enough flex. Wiper may not be effective.	Proper flex. Wiper maintains contact with instrument face and optical window.	Too much flex. Wiper may cause too much friction, using excessive power.

To set this gap:

Fold a piece of paper in half, then in half again, then fold a third time, creasing the edges. It's now 8 sheets thick and about 0.03 in. thick. Make sure the bio-wiper™ is in the closed position. (Open position shown for comparison. In the closed position, the wiper is directly over the optical windows.) You may have to run the instrument to cycle the wiper. If it is not already loosened, loosen the set screw holding the bio-wiper™ and put the paper gage between the instrument face and the bio-wiper. Push down on the bio-wiper™ and rotate it counter-clockwise so that the wiper is in the closed position. Without letting the wiper spring up, tighten the set screw using the factory-supplied hex key until the key deflects about 3/8".

Run the instrument to verify operation.