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       Doc's Corner Article 110-D

Digimet Accessories

Vacuum Fluctuation Test

The Vacuum Fluctuation Test was developed to evaluate vacuum levels and cluster fluctuation while milking high producing cows by utilizing the ten storage areas within the Digimet.

Equipment required:

1. Digimet
2. 3 inch - 12 gauge needle
3. Needle cleaner (0.041" diameter)
4. Silicone sealant

The first four storage slots, within the Digimet, are used for the four calibrated air admission tests used in the Quick Vacuum Stability Test (slot one-20 CFM, slot two-40 CFM, slot three-80 CFM and slot four 120 CFM).

The fifth through the eight storage slots are used for evaluating cluster vacuum levels and fluctuation while milking heavy producing cows.


- As soon as milking unit attached to the cow's udder
- Insert a 12 gauge 3 inch needle through the short milk tube (rubber tube attaching milking liner to stainless steel ferule attaching liner to claw) into the top of the milking claw. Always clean out needle after puncturing milk hose or any hose
-Attach the Digimet to the 12-gauge 3 inch needle within 60 seconds of unit attachment.
- With the Digimet in the vacuum function and five second mode record vacuum level and fluctuations and store in slot five
- Repeat three consecutive times on different high producing cows and store
- Always use sealant in punctured holes after needle removal
- Utilize last two storage slots to store milk line performance when milkers attaching milking units
- Insert 12 gauge needle into milk hose where it attaches to the milk nipple on pipeline for any two cows while milking.
- Record two events - slots nine and ten

▪ This procedure should be performed at monthly intervals to assure that vacuum system performance continues on an optimum basis.
▪ Severe changes in vacuum levels and fluctuation performance would suggest further system evaluation with regards to vacuum pump performance and potential vacuum leaks within the milking system.
▪ This information should be down loaded to computer for permanent records of vacuum system performance

Developed by: Western Dairies, Inc.
Research and Development - Lionel H. Brazil DVM

Doc's Corner is a contribution of Lionel H. Brazil, DVM (1928-2007). Dr. Brazil offered dairy consultation services worldwide for many years. His services covered the following areas: milking management, vacuum system evaluation; and all management procedures relating to mastitis control and SCC reduction.


 Copyrightę 2010 L. J. Engineering, Inc. All rights reserved. Revised: June 8, 2010