Fiber Analyzer A200

Check to ensure the procedures sent with your instrument were followed. Some possible variables that may affect your
results are:

General Problems:

• ND chemicals can come out of solution- Heat and stir to bring back into solution.

• Oven temperature too hot (102°C-105°C +/-2°C)

• Modifying the settings on the Controller

• Improper weighing technique-See weighing technique in the Appendix of the manual.

• Improper or non-use of the desiccant pouch-A standard desiccator will introduce moisture in the samples as it is being opened and closed. This will cause poor precision.

Low Values:

• Grind is too fine

• Bag is not completely sealed

• Broken seam in bag allowing sample to escape from bag

• Digestion run too long (ADF & Crude Fiber)

High Values:

• The movement of the bag suspender is less than 1/2" (1.2 cm) up and down. Refer to your A200 Operator's Manual section titled Initial/Periodic Maintenance.

• Solution is not heated sufficiently-Perform ANKOM Boil Test (see A200 Service Procedure 6)

• ND- Failure to use Alpha Amylase and/or Sodium Sulfite

• AD/ND-Sample too high (>5%) in fat and not pre-treated with solvent

• Crude Fiber-always pre-soak with acetone

• Oven temp low, wet samples introduced next to dry samples-samples are not sufficiently dried.

• Lack of or incorrect use of desiccant pouch-check for holes in pouch, packets not dried regularly-refresh desiccant

• Rinse water not hot enough (70°C+ ND, AD) (50°C +CF) or not long enough (5 minutes)

• Digestion not run long enough

• Acetone re-used for removing water from bags post extraction

• Improper calculation of blank bag correction or using the wrong values in the formula

• Bag sealed too low

• Too much sample in the bag

• Sample not spread out in the bag

• Vessel lid was not closed tightly enough (the tightness of the lid only applies to the A200, A200I, A220)

Our grinding recommendation for samples to be extracted in our Fiber Analyzer is:

1 mm with a Wiley Mill
2 mm with a Cyclone Mill (such as UDY or Retsch)

F57

The porosity of the ANKOM F57 Filter Bag is 25 microns. The design of the filter bag provides a 3 dimensional filter matrix similar to the filtering effect of a glass crucible. The F57 Filter Bag provides equal filtration without the manual intervention required with a crucible method.

F58

The porosity of the ANKOM F58 Filter Bag is 6-9 microns. The design of the filter bag provides a 3 dimensional filter matrix similar to the filtering effect of a glass crucible. The F58 Filter Bag provides equal filtration without the manual intervention required with a crucible method.

Depending on what you are testing, refer to section ADF Analysis, NDF Analysis, or Crude Fiber Analysis in the ANKOM^DELTA Fiber Analyzer Operator's Manual. 

Refer to A200 Service Procedure 19.

The Blank Bag Correction allows for a weight adjustment based on actions that take place during solubilization. The resulting factor adjusts your sample bag weight in an up or downward direction. To determine Blank Bag correction, include at least one empty, sealed and weighed filter bag (blank bag) with your run. After the samples and blank bag have been through the solubilization process and dried as required, divide the final weight of the blank bag by the initial weight. If the samples have been properly prepared, this will result in a factor usually in the 0.992-0.998 range with the F57 filter bag. If the blank bag value is greater than 1.0, refer to question "Why is my blank bag heavier after the run than before the run?"

The MoistureStop Desiccant Pouch is a small, airtight zipper bag, utilized for desiccating all of the Filter Bags that are used with ANKOM instrumentation. A single pouch can hold a full run of F57, F58 or XT4 bags at one time.  When folded, 6 IDF or SDF bags can also be placed into a MoistureStop Desiccant Pouch. Each time a bag has been removed from the desiccant pouch, the air can and should be pushed out. The "zipper" does not have to be used with every bag removal but some action should be taken to keep the air from entering the pouch while the just removed Filter Bag is being weighed. For example, air can be pushed out of the bag by laying it on a firm surface while compressing or flattening the air out of the pouch with your hand.

Many instruments in the marketplace have the capacity to run 6 samples at a time.  After being dried, the beakers, flasks or crucibles are placed into a counter top or cabinet desiccator.  Once cooled, they are then removed one at a time and weighed. Each time the desiccator is opened to remove sample, moist ambient air is introduced inside the desiccator. However, because the lid or door of the desiccator is opened just 6 times, the samples that remain in the desiccator after each item is removed are affected very little by ambient moisture that may be introduced.

However, with Filter Bag Technology, generally larger numbers of Filter Bags are extracted at a time. As with the beakers, flasks and crucibles mentioned above, if the bags are placed in a desiccator after drying, each time the lid or door is opened to remove a bag, moist, ambient air is introduced. Because the desiccator is opened up to 24 times, the moisture can more readily affect the remaining bags. If a collapsible, ANKOM desiccant pouch is utilized, the air can be pushed out of the pouch each time a Filter Bag is removed. This will eliminate a build up of moisture on the remaining Filter Bags and allow for a more accurate and precise result. Every month it is possible to place the small desiccant packets into the oven at 100° - 105°C for a few hours to insure that the desiccant is renewed. In addition, to ensure the integrity of the zip lock bag, regular replacement should be considered.

It is important that the rinse water going into the instrument be at least 50°C for Crude Fiber and 70°C for detergent fibers. For safety purposes, most hot water heaters are set lower than 70°C. In addition, if there is a substantial distance between the instrument and the hot water heater, the rinse water will, at least initially, be even cooler. For these reasons we suggest the purchase of a small hot water heater that can be placed next to the instrument. ANKOM Technology has a small (10 liter) water heater suitable for both the DELTA/DELTAI and the A200/A200I available for purchase.

Rinse water can come directly from the tap. It does not have to be distilled.

It is possible, and may be desirable, to follow an NDF with an ADF using the same sample and Filter Bag. The only drawback is that some samples will produce a lower than expected ADF value when an NDF is run first. The reason for this is that certain components like pectin, tannins, glucans and fructans are removed by NDF solution but not by ADF solution. Therefore, these components are not present in the sample when the ADF follows the NDF. As mentioned above, when you test these types of samples, you will have artificially lower ADF values than you would if you had only run an ADF without the NDF. This issue, of course, has nothing to do with the Filter Bags. They will hold up to both assays with no problem. In fact, you can even follow the ADF with a lignin procedure using the same bags if you wish.

Caution when drying the bags: When running a Lignin procedure or a sequential NDF/ADF or NDF/ADF/Lignin with the F57 Filter Bag, it is important not to dry the bags overnight after the NDF or ADF procedure. A drying timeframe of 2-4 hours at 100° to 105°C is sufficient to thoroughly dry the bags after each procedure. Extended drying times or too high of a temperature can compromise the bag's filtration media.

The F57 filter bag is ash free and therefore can be used for ash determination. See A2000 Service Procedure 34 for the Ashing Procedure.

To prepare the bags, refer to A2000 Service Procedure 33 Ashing Set-up ANKOM F57 & F58 Filter Bags.

Refer to A200 Service Procedure 15.

To enhance the solution flow through the filter, F58 Filter Bags are made from a hydrophilic material. When exposed to 1N sulfuric acid at high temperatures the material can break at the seams. In addition, with some older bag suspenders, the F58 bags are susceptible to abrasion.

• To minimize breakage at F58 Filter Bag seams, you should use the new F58 bags (as of March 2015). The seams of the new bags are strengthened by the addition of point bonds next to the edge of the seal.
• To minimize bag material abrasion, you should use the new bag suspender (as of March 2015 - part # F11). It has been redesigned to include rounded bottom points on each tray.

When neutral detergent solution gets cold, some of the components will begin to precipitate out of solution. As a result, the solution will turn milky white and particles will be floating in it. These particles can be brought back into solution and the solution cleared by heating it. If the container that holds the NDF solution can fit in a lab oven, it is possible to place the solution in the oven over night at 30°C. If this is not feasible or if you need the solution sooner, pour some of the solution into a beaker and heat the solution on a hot plate or in a microwave. When heated, pour the solution back into the main container to warm up the remaining solution. Repeat until all of the solution is clear with no precipitation.

Neutral detergent consists of varying amounts of 4 dry chemicals and triethylene glycol.
If you remove only a portion of the dry chemicals to make less than 20L of solution, it is impossible to know if the solution has the correct ratio of chemicals.
The only way to ensure that the chemical solution consists of the correct ratio of chemicals is to make all 20L at one time.

Test the rinse water with litmus paper during the last minute of the fourth hot water rinse. If the test indicates the presence of acid, repeat with fresh, hot water until neutral pH is achieved.

As you know, amylase is utilized to help digest the starch in the sample.  Even using expired Alpha Amylase, the non-starch components are undoubtedly gone and probably most of the starch also. 
If you put the filter bags in a 1L beaker with 80^o C water and 8 ml of fresh Alpha Amylase and allow the bags to soak for 20-30 minutes, that should take care of any residual starch.  If you have an A200 Fiber Analyzer, you could put the bags in the bag suspender, place them in the instrument with the heat off (you don’t want boiling water) and turn on the agitation.  After 20-30 minutes rinse the bags once for 5 minutes, dry and weigh.

With the lignin procedure, there are two common errors that will create false high values.

The first error is placing the F57 Filter Bags into the 72% sulfuric acid when there is moisture in the bags and samples. To avoid this situation, once the ADF procedure is complete and the Filter Bags have been dried and weighed, place the Filter Bags back into the oven at 100^o to 105° C for 30 to 60 minutes. When the bags have been dried, place them into a desiccant pouch and allow them to cool to room temperature. Once they have been cooled, immediately place them into the 72% sulfuric acid and begin the procedure.

The second error occurs in the rinsing of the bags after the three-hour soaking in 72% sulfuric acid. It is vital that all of the acid is rinsed out of the bags before the F57’s are placed into the oven for drying. The rinsing process uses copious amounts of fresh water. After several minutes of rinsing, touch several bags with litmus paper. If the litmus paper shows the presence of acid in any of the bags, continue the rinsing for several more minutes and test again. Continue to test the bags with litmus paper until no bags show the presence of acid. At this point, place the bags into a beaker, pour enough acetone to cover the bags and soak for 3 to 5 minutes. When the soaking is complete, pour off the acetone, lay them on a clean surface, and allow the acetone to evaporate from the bags. Place the filter bags into the oven at 100° to 105° C for at least two hours. When the bags have been dried, place them into a desiccant pouch and allow them to cool to room temperature. Once they have been cooled, weigh the bags one final time.
 

During a crude fiber or acid detergent procedure, the time frame during which samples are exposed to 100°C solution(s) is extremely important.  If the fiber analyzer begins a procedure at a temperature higher than 20°C, the instrument will heat the solution too quickly and the effective digestion time frame will be too long.  This will create lower than expected fiber values.  As a result, when performing back-to-back fiber runs with the second being a crude fiber or acid detergent procedure, we would suggest pouring cold water into the vessel prior to the second run in order to cool the instrument to room temperature.

Possible Causes:

The dial on the heat sealer may not be turned up high enough. In order to seal the F57 Filter Bag, the dial must be set at approximately "4" while the XT4 Filter Bag is sealed at a setting of "6." Different lab conditions may effect the proper setting. Experiment with a bag to "dial in" the correct setting.

The heating element is broken. On the sides of the Teflon cover are two shiny metal strips that keep the cover in place. Loosen the screws that keep the strips tight to the base of the heat sealer and remove the Teflon cover. Check to see if there is a break in the heating element. If there is, take the extra heating element from the box that the heat sealer came in and replace the defective element. Additional elements can be ordered from ANKOM Technology.

The Insulator is not properly installed. The insulator should be installed to ensure that the heating element does not touch any of the metal on the base of the heat sealer.

The instrument is experiencing a pressure fault.  There are three possible reasons for this fault.

1. More than 2 L of solution was in the vessel during the digestion process.

A pressure fault will most commonly occur if there is more than 2 L of solution in the vessel during the digestion process, leaving a small head space.  Never use more than 2 L of solution in the vessel during the digestion process.

2. Metal parts within the vessel are experiencing corrosion.

If the solution level is below 2 L and the instrument is running acid detergent, it is possible that corrosion of metal inside the vessel is producing additional gas that increases the pressure inside the vessel. Check for corrosion in the following areas:

• inside the wall of the vessel

• agitator disk in the bottom of the vessel

• metal parts of the bag suspender (including the weight)

Corroded parts must be replaced.

3. The pressure switch has failed.

If you are not using more than 2 L of solution and the metal parts in your vessel are not corroded, replace the pressure switch (refer to A200 Service Procedure 10 for instructions).

The instrument is experiencing a high temperature fault.  If your controller is set for 100°C , there are two possible reasons for this fault.

1.  The agitation is not working properly during an assay. 

To check the agitation during an assay, remove the back panel of the instrument and do the following:

• Check that the motor fan is spinning (refer to A200 internal components).  If the motor is not spinning, turn off and unplug the instrument.  Then loosen the brass packing nut 1/2 turn and check the wiring connections to the motor.  Plug the instrument back in and press the Agitate button.  If the motor starts to turn, reset the packing nut (refer to A200 Service Procedure 4 for instructions).  if the motor does not turn after loosening the packing nut and the wiring connections are good, replace the motor (refer to A200 Service Procedure 7 for instructions).

• Check that the agitator shaft is spinning (refer to A200 internal components - look between the Maintenance Alert Collector and the Helical Coupler).  If the motor fan is spinning, but the agitator shaft is not spinning, then one or both of the set screws on the Helical Coupler need to be tightened.  Turn off and unplug the instrument before tightening the set screws.

2. The actual temperature has exceeded the ETS capacity and must be replaced.

To replace the ETS, remove the back panel of the instrument and locate a black object bolted to the upper left side of the vessel (refer to A200 internal components).  NOTE: Attached to the bottom of the ETS is an orange wire and attached to the top is a cloth covered wire. Disconnect the existing ETS and install a new one in its place.

See A200 Service Procedure 5.

To ensure that the controller settings are correct: see A200 Service Procedure 2 (for instruments purchased pre 9/03) or see A200 Service Procedure 1 (for instruments purchased Post-09/03)

If settings are correct you will need to test the controller and calibrate it. To test the controller see A200 Service Procedure 6.

Possible Causes:

• The person operating the instrument did not put enough solution into the vessel to cover all of the trays.

• The exhaust valve is slightly open and some of the solution slowly drips out of the vessel during the extraction.

• The red heat button is not turned off at the end of the extraction after the solution has been drained from the instrument and the trays are left in the instrument.

• There is an adequate amount of solution and the heat is on but the agitation is not turned on.

If bag suspender trays are melted you should do the following:

1).  Replace melted trays see links below for:

Bag Suspender w/ weight
Bag Suspender Tray (bottom)
Bag Suspender Tray (top)

2).  Inspect inside of vessel to determine if any plastic melted to the walls.  If so, fill vessel with water and turn on heat until the water boils. Turn off heat.  Carefully scrap the plastic from the walls and remove plastic pieces.  Drain water and wipe out any remaining plastic residue.

When the pressure in the vessel is too high, the pressure switch will turn off the heater.

Possible Causes:

There is too much solution in the vessel. Make sure 2 liters or less of solution is used in the vessel at a time.

The motor is not turning or is stalling during a run which will cause a higher temperature in the vessel and thereby raising the pressure. Check to make sure the fan is on the motor. Replace the fan if needed. See A200 Service Procedure 7.

There is a corrosion problem. Inspect the agitator, the bag suspender weight, and the bag suspender rod to see if any corrosion is taking place.

The controller is not calibrated and heater higher than it should. See A200 Service Procedure 6.

The bag suspender is sticking in vessel. See A200 Service Procedure 16.

All of the above cause a pressure failure. When this occurs, the heat lamp will go out and the temperature will drop until the pressure is lowered sufficiently (generally below 90oC) at which time the heat will come back on and will continue to cycle on and off.

When the temperature in the instrument becomes too high, the heat will shut down but the heat lamp will remain on. When the temperature drops sufficiently (generally below 90oC) the heat will come back on and will continue to cycle on and off.

Possible Causes:

Motor wires are loose or disconnected. Unplug the instrument. Inspect the wiring to the motor. Contact ANKOM if a loose or disconnected wire is found.

If wires are intact run this test: Turn the instrument on and press the blue "Agitate" button. Check to see if the motor is turning. (The fan at the bottom of the motor will spin if the motor is turning.)

The Motor Set Screw(s) is too loose. If the motor is turning but the agitator is not, you will need to tighten the set screw(s) on the gray coupler with an Allen wrench. Note: Be sure to unplug the instrument before tightening the set screws.

The Packing Nut is too tight. If the motor is not turning when the "Agitate" button if pressed, you may need to loosen the brass packing nut.

1. Unplug the instrument.
2. Loosen the brass packing nut so you can turn it easily with your fingers.
3. Reach down into the vessel and twist the agitator disk back and forth a couple of times
4. Plug the instrument back in.
5. Turn the instrument on and press the blue "Agitate" button.
6. If the agitation begins, tighten the brass packing nut until you hear the motor begin to labor (you will hear the tone of the motor change slightly). When the tone changes, loosen the brass packing nut 1/8 of a turn and the tone will change back. This is the appropriate tightness.

The agitator may have corrosive buildup. If periodic maintenance was ignored and acid solution was allowed to leak into the packing assembly, the shaft may become "frozen". Check for corrosive buildup. The packing set and agitator may need to be replaced.

The motor may have failed. This is a bit unusual and each of the above possibilities should be investigated thoroughly before ordering a motor. If all of the above steps have been reviewed and the agitator still does not turn, the motor will need to be replaced.