MEASURING - 7 - NMC TESTING_Vacuum Differences and Falloff

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* 1. Enter your first and last name

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* 2. The operating vacuum is the:

average vacuum measured at different locations in the milking machine during a dry test with all milking units connected to the machine, the pulsators operating, and all teatcups plugged

average vacuum measured at different locations in the milking machine during a dry test with all milking units disconnected from the machine, the pulsators off, and all teatcups plugged

average, minimum, and maximum vacuums measured at different locations in the milking machine during a wet test

average vacuum measured at different locations in the milking machine during a wet test with all milking units connected to the machine, the pulsators operating, and all teatcups unplugged

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* 3. Select all of the correct statements regarding the operating vacuum measurement.

Before measuring the operating vacuum, the vacuum pump should run for at least 10 minutes.

The operating vacuum measurement must be performed with the regulator connected and operational in as close to an "as milking" condition as possible.

Before measuring the operating vacuum, the vacuum pump should run for at least 30 minutes.

The operating vacuum measurement must be performed with the regulator disconnected to avoid interference.

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* 4. Select all that apply. The operating vacuum should be measured at the following locations:

In the receiver

At the sensing point of the vacuum regulator

In the pulsator airline farthest from the vacuum source

At the the vacuum pump inlet

In the claw

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* 5. Select all of the correct statements regarding the operating vacuum measured at the receiver and at the vacuum regulator sensing point.

The difference between these two operating vacuum levels should be 0.7 kPa (0.2 inches of mercury) or less.

The difference between these two operating vacuum levels should be 2 kPa (0.6 inches of mercury) or less.

Differences greater than 0.7 kPa (0.2 inches of mercury) may result in reduced regulation sensitivity.

Differences greater than 0.7 kPa (0.2 inches of mercury) are due to excessive restrictions in pipelines and fittings between the receiver and regulator sensing point.

This test is performed while admitting air equivalent to one unit fall-off.

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* 6. Select all of the correct statements regarding the operating vacuum measured at the vacuum pump inlet and receiver.

The difference between these vacuum measurements should not exceed 2 kPa (0.6 inches of mercury).

The difference in these vacuum measurements should not exceed 0.7 kPa (0.2 inches of mercury).

This test should be performed with the regulator disabled.

Excessive vacuum drop between the receiver and vacuum pump may be due to excessive tees or elbows in the main air line.

Excessive vacuum drop between the vacuum pump and receiver may be due to unreasonably high airflow (over-sized vacuum pump) for the size of the lines.

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* 7. The unit fall-off test is a more direct measure of sufficient effective reserve (made by admitting air with an air-flow meter) since it uses the milking units installed on each system.

True

False

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* 8. Select all that apply: Match the components of vacuum change for the unit fall-off test to their corresponding required vacuum measurements and calculations.

receiver operating vacuum (ROV): average vacuum level in the reciever with milking unit(s) admitting no extra air.

vacuum drop (VD): ROV minus the average stabilized vacuum level when milking unit(s) is(are) fully opend and admitting air.

under-shoot: stabilized average vacuum when milking units are fully opened and admitting air MINUS the minimum vacuum level measured as 1 or 2 unit(s) is(are) opened.

over-shoot: maximum vacuum level measured as the unit(s) is(are) closed minus ROV

receiver operating vacuum (ROV): stabilized average vacuum when milking units are fully opened and admitting air MINUS the minimum vacuum level measured as 1 or 2 unit(s) is(are) opened.

under-shoot: average vacuum level in the reciever with milking unit(s) admitting no extra air.

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* 9. Select all of the correct statements about the unit fall-off test

The fall-off test should be performed with one milking unit for small (32 or fewer milking units and one operator) milking machines.

The fall-off test should be performed with two milking units for large (more than 32 milking units and 2 or more operators) milking machines

The fall-off test should be performed with three or more milking units for extra large milking machines.

The fall-off test is designed to determine if the milking machine can maintain the receiver vacuum level within certain limits in the event of a unit fall-off.

The fall-off test is designed to determine if the operators are using the milking machine correctly.