SETUP:
1) The "MonoG" is made from acrylic plastic. Do not clean it with strong aromatic solvents. Do not risk the possibility of crazing the surfaces of the instrument. Use detergent and water only! Acrylic will not tolerate temperatures much above 140° F. without deforming in time.
2) Start by removing the top of the reservoir (There is a finger nail grove around bottom edge of lid to facilitate this) and placing 1 cc of the surfactant and 1.5 cc of the dye into the reservoir. Add ~260 cc of distilled water.
3) Place the instrument on as level a surface as is available next to the water bath noting the caveat of item 5.
4) With lid still off the reservoir and the reservoir/manometer assembly detached from the reaction vessel and its tube, add or remove distilled water with a small syringe to set the bottom of the meniscus in the manometer tube to zero on the scale. Press the reservoir lid back into place. It is rather tight on purpose as o-ring friction is what keeps the lid in place under the small head developed during use.
5) Slip the gas hose that connects the reaction vessel to the reservoir onto the hose barb of the reservoir. Keep the hose as short as possible but long enough to keep the instrument clear of sources of direct heat or cold. Having the instrument in a drafty location or immediate to a poorly insulated water bath will adversely impact accuracy. Alternately, the instrument may be placed in the bath with the reaction vessel to assure thermal stability. This works best with the addition of the digital interface for obvious reasons.
6) Place the evaporation barrier disk in place on top of the manometer tube if it has come loose during shipping.
7) Detached hose from the reaction vessel. Make sure that the instrument is reading zero before starting each test. A bubble across the hole in the reservoir inlet hose barb or bubbles in the gas hose have sufficient surface tension to keep the levels from equilibrating. Blow gently through the hose to clear it in this event.
8) Allow your water bath to come to temperature and stabilize (Most testing is done at 30° C.). Make sure that the MonoG has come to room temperature (or bath temperature) and stabilized.
9) The fresh water in the MonoG reservoir will, of course, absorb CO2 etc. until it has become saturated. Make up some experimental batches of your testing standard and run three or four of them through the instrument to condition the fluid and get used to reading the instrument. Don't worry about leaving the instrument unattended as the gas will start bubbling through before it overflows the manometer.
10) Test procedure: Prepare samples as per AACC Method 89-01 or in a comparably rigorous manner depending on purpose of test. For yeast gassing power testing, an alternative method is described below. Place test dough or slurry aliquot in reaction vessel, cap the reaction vessel and place in water bath (do not have the hose attached to fitting in cork or lid during placement of lid). Sink the reaction vessel up to just below the lid or cork. The instrument is provided with a glass stirring rod and removable rubber handle. If you are using the slurry method as outlined below, it works best to remove handle after mixing and leave the rod in the reaction vessel so that there is no drag out of sample.
11) Allow contents and reaction vessel to equilibrate to bath temperature before connecting gas hose to fitting on reaction vessel. (Method 89-01 stipulates 5 min.)
12) Note and log time at which hose was connected.
13) If a time rate record is required, then it is necessary to log the manometer reading manually at the selected time intervals. (The electronic interface will save hours in labor costs and reading errors if frequent time/rate information is needed). If an end point reading is all that is required, set a timer when you connect the gas hose to reservoir and read level of manometer in GUs (Gasograph units) at end of desired interval.
14) If you are doing in-lab day to day comparative testing then the slight curvilinearity of response is of no consequence. If conversion to cc STP is needed, utilize the calibration curve optionally provided with the instrument or multiply GU by 2.35.
General comments - Consistency of procedure and accurate preparation of your samples is the path to reliable results with any analytical test instrumentation. The MonoGaso, simple as it is, is no exception. Each user will eventually develop their own preferred techniques. Start off by evaluating samples of the formulas and ingredients that are currently providing acceptable product quality. For yeast viability, establish a base line with these ingredients using an accepted AACC Standard Method or the alternate method as described below. Do not change more than one ingredient at a time and always reference that ingredient's performance back to the starting standard. Obviously, running multiple samples (3 or more) and taking the mean is the most accurate way to establish reliable data points, though careful and consistent sample preparation will go a long way toward building confidence in the instruments single sample accuracy. In the original Gasograph collaborative study done by the USDA Western Wheat Lab and the USDA Grain Marketing Lab coefficients of variablility between labs was less than 1% for all twelve channels at the three different yeast levels used. Two to four MonoGaso set side by side helps greatly here, as having two or more samples running simultaneously speeds up the process and makes visual comparison quick and easy. Keeping track of this information gives the end user a means to watch trends in ingredient quality and supplier performance. KEEP GOOD LABORATORY RECORDS!
Proofing height-
The glass 1/2 pt. reaction vessel has graduations and may be used for proof height estimations in doughs at the same time as total gassing power is measured.
Place in reaction vessel 15 ml water containing 0.15 g of NaCl, 0.60 g of sucrose, and either 0.2, 0.35, or 0.725 g of fresh bakers yeast unless otherwise determined. Add 10 g flour (14% mb) and mix slurry for 1.5 min. with short glass rod that has removable rubber handle. Leave stir rod in reaction vessel. Press stopper or lid into place and latch as in the case of the stainless steel reaction vessel. Place reaction vessel into water bath at 30° C. Allow 2 minutes to elapse before attaching hose to manometer. Note and record this starting time. Record reading in GU on manometer after 90 minutes. For digital model users, initiate data acquisition at hose connection.
Note: Equilibration occurs more rapidly if liquid ingredients and reaction vessel are placed into water bath for a few minutes prior to adding the flour and yeast.
[ Project examples] | [Filter Assembly] | [ Reaction Vessel] | [ Business Philosophy] | [ Warranty] |