mined by the Ammonia Quick Test and the passive dosimeter tube, were compared to the ammonia concentration determined by the gas detector tube.
61995 Applied Poultry Science, I n c
AMMONIA QUICK TESTAND AMMONIA DOSIMETER TUBES FOR DETERMINING AMMONIA LEVELS IN BROILERFACILITIES' I? A. SKEwES2 Clemson Universiy, Poultty Science Department, Clemson, SC 29634-0379 Phone: (803) 656-3163 FAX: (803) 656-1033 J. D. HARMON Iowa State Universitj, Department ofAgricullural mid Biosystems Etigirieeriitg, Antes, IA 50011-3080
Primarv Audience: Field Service Personnel. Contract Producers
SUMMARY els in poultry facilities mendation is to keep ammon y, a reliable, inexpensive method of determining ammonia levels has not been well established. To address this situation, ammonia concentrations, as determined by the Ammonia Quick Test and the passive dosimeter tube, were compared to the ammonia concentration determined by the gas detector tube. The Ammonia Quick Test estimated ammonia levels accurately at levels of 20-25 ppm of ammonia. The dosimeter tubes estimated average ammonia levels accurately a t low levels of a Comparisons of ammonia concentration to relative humidity suggest that ammonia can rapidly than relative humidity. lity, ammonia, broilers, dosimeter tubes, gas detector tubes, rela
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producer. Currently, most producers and serDESCRIPTION OF PROBLEM vice personnel rely on their sense of smell to The negative effects of excessive ammonia concentration on poultry has been well documented [l]. Based on this fact, management guides continue to stress the importance of keeping ammonia levels in animal environments below a certain point. Although this is an excellent goal, the tools to accomplish this goal are not readily available to the poultry
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evaluate ammonia concentrations in poultry houses. It has been suggested that prolonged exposure will reduce the sensitivity of the nose to ammonia. The level of sensitivity of the nose is 53 ppm [2], considerably above the 25 ppm recommended by Reese et al. [3]. The need for an ammonia measuring device for use in the field is obvious. Although
Reference to product names does not indicate endorsement To whom correspondence should be addressed
Research Report S K E W S and HARMON
the ammonia gas detector tube provides measurements of ammonia concentration comparable to those obtained with standard titration techniques [4], its use by growers has been limited due to the cost of the sampling pump ($3W$400) and the cost per test sample ($3-$4). The passive dosimeter tube does not require a sampling pump and is similar to the gas detector tube in principle and in cost per sample. Dosimeter tubes provide time weighted averages of gas concentration. Electronic ammonia sensors are also available, but they have not been well accepted due to high initial costs, difficult calibration, and the need for routine maintenance [5]. The Ammonia Quick Test, distributed by Vineland Laboratories, provides a simple and inexpensive test for ammonia. Neither the dosimeter tube nor the Ammonia Quick Test have been properly tested in the poultry environment. In an effort to provide poultry service personnel and managers with a practical method of estimating ammonia concentrations in poultry facilities, the Ammonia Quick Test and the passive dosimeter tube for ammonia were compared to the ammonia gas detector tube. The necessity of making the manufacturers’ recommended temperature corrections was also examined. Eliminating the temperature correction would make field sampling easier. Additionally, it has been shown that high relative humidity in a broiler house will result in higher levels of ammonia [6]; thus, regulating ventilation based on humidity may successfully control ammonia. To determine if this approach might work, relative humidity was compared to ammonia concentration. The objective of this study was to evaluate dosimeter tubes and the Quick Test to determine if they would be suitable for grower usage.
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provide environments with increasing ammonia concentration. No mechanical ventilation was used in these three houses. Air quality was monitored at three locations (both ends and middle) of eight houses for a total of twentyfour sampling locations. Starting at 8:OO p.m., 2-hr sampling cycles were initiated as follows: starting at the fan end of the first house a passive dosimeter tube was prepared for sampling by breaking off both ends of the glass tube and exposing the contents of the tube to the environment. The tube was suspended approximately 30 cm (12 in.) above the litter. At the same location a gas detector tube determined ammonia concentration and a sling psychrometer determined wet bulb and dry bulb temperature. This process was repeated at the middle of the house and the opposite end of the house. This procedure was then continued through the remaining seven houses. The eight house cycle required approximately two hours, at which time it was repeated starting with the first house. A dosimeter tube remained at each of the twenty-four locations for the duration of the study providing timeweighted average (TWA) ammonia concentrations. Sampling equipment for this study included: 1) The Gastec Passive Dosimeter Tube No. 3D, which has a measurement range of 25-500 ppm/hr for a maximum of a IO-hr sample, 2 ) Gastec Ammonia Low Range Detector Tube No. 3La with a measurement range up to 200 ppm using a 50 mL air sample, and 3) Ammonia Quick Test, a color change reaction with a range of 0-100 ppm listed on the color chart provided with the test kit. At the conclusion of the study, the wet bulb/dry bulb readings were converted to percent relative humidity utilizing a psychrometic chart. Temperature corrections were made to the gas detector tube and passive dosimeter tube readings as prescribed by the manufacturer. Ammonia concentration and relative humidity data collected at each location were compared to the ammonia level as determined by the gas detector tube, which has been documented as an accurate system for measurement of ammonia in poultry houses [4]. The passive dosimeter tube provides an accumulated concentration of ammonia. To obtain a time-weighted average, the reading
MATERIALS AND METHODS The ammonia concentration, dry bulb temperature, and wet bulb temperature of eight commercial broiler houses on one farm were monitored over a single 10-hr period (8:OO p.m. to 6:OO a.m.). Five houses contained broilers of approximately 2 wk of age and were ventilated by conventional negative pressure to provide minimum ventilation. Three houses did not contain birds and were provided with three levels of restricted natural ventilation to
AMMONIA LEVEL DETERMINATION
150 is divided by the exposure time. To compare these values to the actual average ammonia concentration, the gas detector tube values were averaged for a given location over the 10-hr test period.
less accurate. All readings greater than 60 ppm came from the closed houses where no ventilation was provided. This finding does not represent the typical conditions found in the field. The passive dosimeter tube did accurately estimate the TWA under moderately consistent environmental conditions; therefore, it could be used to monitor ammonia levels over a 10-hr period under typical conditions. The passive dosimeter tube may not, however, be able to accurately determine the TWA of ammonia concentration resulting from a faulty ventilation system. Although it has been shown that as relative humidity increases ammonia levels increase [6] (suggesting that relative humidity might be a good indicator of ammonia concentration), this finding does not appear to occur consistently in these tests (Figure 3). Although the lowest humidity did coincide with the lowest ammonia concentrations, the relative humidity stayed fairly constant (70-90%) as ammonia concentrations increased from 20 to 200 ppm. The temperature correction factors provided by the manufacturer result in very little deviation from the uncorrected values as shown in Figure 4 for the detector tubes and Figure 5 for the passive dosimeter tubes. Under typical field conditions the temperature corrections would not be necessary.
RESULTS AND DISCUSSION A comparison of the average of all samples tested using each method appears in Table 1. Individual graphs are presented in Figures 1-5. In Figures 1-5 the x axis represents the actual ammonia concentrations as determined by the gas detector tube. The y axis represents the test measurements. The Ammonia Quick Test accurately estimated ammonia levels when the ammonia level was 20-25 pprn (Figure 1). However, the estimation of the ammonia level by the Ammonia Quick Test increased in inaccuracy as the actual ammonia concentration either decreased or increased from the 20-25 ppm level. The passive dosimeter tube, which provides a TWA, appears to have a similar but less severe fault by underestimating ammonia concentrations at high levels (Figure 2). The TWA given by the passive dosimeter tube closely represents the actual average ammonia concentration at approximately 20 ppm. As ammonia concentrations increased, the dosimeter tube readings became
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CONCLUSIONS AND APPLICATIONS 1. The Ammonia Quick Test provides a reasonably accurate estimation of ammonia concentrations when levels are near 20-25 ppm. Above or below this level, accuracy is rapidly
compromised. 2. The passive dosimeter tube provides an accurate time-weighted average of ammonia concentrations under typical management conditions where levels are not rapidly increasing during a short period of time. 3. The passive dosimeter tube is moderately expensive, costing $3.00 per sample, but it may still be the best method for field determination of ammonia concentrations. The detector tubes, while more accurate, give only an instantaneous reading, requiring the operator to be present. 4. NH3 tends to increase slightly with RH, but this relationship would not allow using relative humidity as the sole criterion for controlling ammonia. 5. Adjustment of raw values for detector tubes and dosimeter tubes based on variation of ambient temperature was not necessary to obtain reasonable accuracy.
1. Carlile, F.S.,1984. Ammonia in poultry houses: A literature review. World's Poult~ySci. J. 40:99-113.
ing resistance to infection with h'ewcastle disease. Avian DIS.8~369-379.
2. The Merck Index, 1976. An Encyclopedia of Chemicals and Drugs.9th Edition. M. Windholz, ed. Merck & Co.,Inc., Rahway, NJ.
5 . Ross, C.C. and W.D. Daley. Evaluation of Electronic Ammonia Sensors for Poultry Housing. Project Nos. A4935 & N 400-970. Georgia Institute of Technology, Atlanta, GA.
3, Reese, F,N,, D,D, IAN, and
Jaw.Dealon,
1980.
Ammonia in the atmosphere during broodingarfects performance of broiler chickens. Poultry Sci. 59:486488. 4. c-w* and R.P* 1964.The adverse effects of ammonia on chickens includD.P*j
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6. Weaver, W.D. and R. Meijerhuf, 1991. The effect of different levels of relative humiditvand air movement on litter conditions, ammonia levels, growlh, and carcass quality for broiler chickens. Poultry Sci. 70:74&755.
