EMC Charts

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
Equilibrium Moisture Content Charts for Grain Storage Management 
The equilibrium moisture content (EMC) of air can be used to predict how the ambient air used for natural 
air drying (NAD) will affect the moisture content of grain. The EMC of the air depends on its temperature 
and relative humidity (RH) as well as the grain type.  
The EMC represents the moisture content that the grain will eventually equilibrate to if the air conditions 
remain constant for a length of time. Although air conditions are rarely constant for longer than an hour, 
the EMC information can still be used to determine the range of air temperatures and relative humidities 
that will achieve drying.  
For example: if the ambient air has a temperature of 10°C and a RH of 60%, the EMC of the air for 
WHEAT is 13.6% (refer to EMC chart below). That means that if the air conditions stay constant at 10°C 
and 60% RH, wheat would eventually equilibrate to 13.6% moisture content (and 10°C). Whether the 
wheat started with a moisture content lower or higher than 13.6% doesn’t matter; the wheat would 
eventually equilibrate to 13.6%. 
Another example: if the goal is to dry wheat to 14.4%, the most effective time to run the fan would 
be when the EMC of air is less than 14.4%. Those conditions (air temperature and RH) are highlighted in 
red in the chart below.  
EQUILIBRIUM MOISTURE CONTENT FOR HARD RED SPRING WHEAT  
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
10.7 
11.4 
12.0 
12.7 
13.5 
14.2 
15.0 
15.9 
16.9 
18.0 
19.3 
2 
10.4 
11.1 
11.8 
12.5 
13.3 
14.0 
14.8 
15.7 
16.7 
17.8 
19.1 
5 
10.3 
11.0 
11.7 
12.4 
13.1 
13.9 
14.7 
15.5 
16.5 
17.6 
19.0 
8 
10.1 
10.8 
11.5 
12.2 
13.0 
13.7 
14.5 
15.4 
16.4 
17.5 
18.9 
10 
10.0 
10.7 
11.4 
12.1 
12.9 
13.6 
14.4 
15.3 
16.3 
17.4 
18.8 
13 
9.9 
10.6 
11.3 
12.0 
12.7 
13.5 
14.3 
15.2 
16.2 
17.3 
18.7 
15 
9.8 
10.5 
11.2 
11.9 
12.6 
13.4 
14.2 
15.1 
16.1 
17.2 
18.6 
18 
9.6 
10.3 
11.0 
11.8 
12.5 
13.3 
14.1 
15.0 
16.0 
17.1 
18.5 
22 
9.4 
10.2 
10.9 
11.6 
12.3 
13.1 
13.9 
14.8 
15.8 
16.9 
18.3 
26 
9.3 
10.0 
10.7 
11.4 
12.2 
12.9 
13.8 
14.6 
15.6 
16.8 
18.2 
28 
9.2 
9.9 
10.6 
11.3 
12.1 
12.8 
13.7 
14.6 
15.6 
16.7 
18.1 
 
REMEMBER that it is also important to manage grain temperature as well as moisture content to 
help prevent spoilage. If you are using warm air (temperature greater than 15°C) to help dry grain, the 
grain will also warm to that temperature. Once the target moisture content has been reached, aerate 
with cool air to bring the average grain temperature below 15°C. Due to the effect of grain temperature 
on the air’s ability to remove moisture, this cooling period will also result in some moisture loss, so 
cooling can start once the grain is within approximately half a percent of the target moisture content. 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
Also note that if the grain temperature is considerably different than the air temperature, the EMC of 
the air will be difficult to determine until the temperature of the air and grain equalizes (usually within 6 
to 24 hours of fan operation, depending on airflow rate).   
IMPORTANT NOTE: The EMC of air depends on the grain type as well as the air temperature 
and RH. The EMC charts for wheat, barley, peas, canola, oats, lentils, soybeans, barley, flax, and 
sunflowers are presented below.  
 
These charts are based on the moisture isotherm data summarized in the ASABE Standard D245.5 
(Moisture Relationships of Plant-based Agricultural Products) and various published studies (listed after 
the charts). These charts use the modified Henderson model for flax, peas and canola, the modified 
Chung-Pfost model for flax, oats, hard red spring wheat and barley, the modified Halsey equation for red 
lentils, soybeans and sunflowers, and the modified Oswin model for lentils, durum and oats.  Note that 
much of the information in ASABE Standard D245.5 is based on research conducted in the 1980’s and 
1990’s. Since that time, plant breeding has resulted in different starch and oil contents of grains and 
oilseeds which may affect the EMC values. Therefore, these charts should be used as a guideline only.  
 
EQUILIBRIUM MOISTURE CONTENT FOR HARD RED SPRING WHEAT (Modified Chung-Pfost) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
10.7 
11.4 
12.0 
12.7 
13.5 
14.2 
15.0 
15.9 
16.9 
18.0 
19.3 
2 
10.4 
11.1 
11.8 
12.5 
13.3 
14.0 
14.8 
15.7 
16.7 
17.8 
19.1 
5 
10.3 
11.0 
11.7 
12.4 
13.1 
13.9 
14.7 
15.5 
16.5 
17.6 
19.0 
8 
10.1 
10.8 
11.5 
12.2 
13.0 
13.7 
14.5 
15.4 
16.4 
17.5 
18.9 
10 
10.0 
10.7 
11.4 
12.1 
12.9 
13.6 
14.4 
15.3 
16.3 
17.4 
18.8 
13 
9.9 
10.6 
11.3 
12.0 
12.7 
13.5 
14.3 
15.2 
16.2 
17.3 
18.7 
15 
9.8 
10.5 
11.2 
11.9 
12.6 
13.4 
14.2 
15.1 
16.1 
17.2 
18.6 
18 
9.6 
10.3 
11.0 
11.8 
12.5 
13.3 
14.1 
15.0 
16.0 
17.1 
18.5 
22 
9.4 
10.2 
10.9 
11.6 
12.3 
13.1 
13.9 
14.8 
15.8 
16.9 
18.3 
26 
9.3 
10.0 
10.7 
11.4 
12.2 
12.9 
13.8 
14.6 
15.6 
16.8 
18.2 
28 
9.2 
9.9 
10.6 
11.3 
12.1 
12.8 
13.7 
14.6 
15.6 
16.7 
18.1 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR HARD RED WINTER WHEAT (Modified Oswin) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
10.2 
11.2 
12.3 
13.4 
14.6 
15.9 
17.4 
19.1 
21.1 
23.6 
26.9 
2 
10.0 
11.0 
12.0 
13.2 
14.3 
15.6 
17.1 
18.8 
20.8 
23.2 
26.5 
5 
9.9 
10.8 
11.9 
13.0 
14.1 
15.4 
16.9 
18.5 
20.5 
23.0 
26.2 
8 
9.7 
10.7 
11.7 
12.8 
14.0 
15.2 
16.7 
18.3 
20.3 
22.7 
25.9 
10 
9.6 
10.6 
11.6 
12.7 
13.8 
15.1 
16.5 
18.1 
20.1 
22.5 
25.7 
13 
9.5 
10.4 
11.4 
12.5 
13.6 
14.9 
16.3 
17.9 
19.8 
22.2 
25.4 
15 
9.4 
10.3 
11.3 
12.4 
13.5 
14.7 
16.1 
17.7 
19.6 
22.0 
25.1 
18 
9.2 
10.2 
11.2 
12.2 
13.3 
14.5 
15.9 
17.5 
19.4 
21.7 
24.8 
22 
9.0 
10.0 
10.9 
11.9 
13.0 
14.2 
15.6 
17.2 
19.0 
21.3 
24.4 
26 
8.9 
9.8 
10.7 
11.7 
12.8 
14.0 
15.3 
16.8 
18.7 
20.9 
24.0 
28 
8.8 
9.7 
10.6 
11.6 
12.6 
13.8 
15.1 
16.7 
18.5 
20.7 
23.7 
 
 
EQUILIBRIUM MOISTURE CONTENT FOR DURUM WHEAT (Modified Oswin) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
8.8 
9.7 
10.7 
11.7 
12.7 
13.9 
15.3 
16.8 
18.6 
20.9 
23.9 
2 
8.7 
9.6 
10.5 
11.5 
12.6 
13.7 
15.0 
16.6 
18.4 
20.6 
23.6 
5 
8.6 
9.5 
10.4 
11.4 
12.4 
13.6 
14.9 
16.4 
18.2 
20.4 
23.4 
8 
8.5 
9.4 
10.3 
11.3 
12.3 
13.4 
14.7 
16.2 
18.0 
20.2 
23.2 
10 
8.4 
9.3 
10.2 
11.2 
12.2 
13.3 
14.6 
16.1 
17.9 
20.1 
23.0 
13 
8.4 
9.2 
10.1 
11.0 
12.1 
13.2 
14.5 
15.9 
17.7 
19.9 
22.8 
15 
8.3 
9.1 
10.0 
11.0 
12.0 
13.1 
14.4 
15.8 
17.6 
19.8 
22.7 
18 
8.2 
9.0 
9.9 
10.8 
11.8 
13.0 
14.2 
15.7 
17.4 
19.6 
22.4 
22 
8.1 
8.9 
9.7 
10.7 
11.7 
12.8 
14.0 
15.4 
17.1 
19.3 
22.1 
26 
7.9 
8.7 
9.6 
10.5 
11.5 
12.6 
13.8 
15.2 
16.9 
19.0 
21.8 
28 
7.9 
8.7 
9.5 
10.4 
11.4 
12.5 
13.7 
15.1 
16.8 
18.9 
21.7 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR BARLEY (Modified Chung-Pfost) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
11.2 
11.9 
12.6 
13.3 
14.1 
14.8 
15.7 
16.6 
17.6 
18.7 
20.1 
2 
10.9 
11.6 
12.3 
13.0 
13.8 
14.6 
15.4 
16.3 
17.3 
18.5 
19.9 
5 
10.7 
11.4 
12.1 
12.8 
13.6 
14.4 
15.2 
16.1 
17.1 
18.3 
19.7 
8 
10.5 
11.2 
11.9 
12.6 
13.4 
14.2 
15.0 
15.9 
16.9 
18.1 
19.5 
10 
10.3 
11.1 
11.8 
12.5 
13.3 
14.1 
14.9 
15.8 
16.8 
18.0 
19.4 
13 
10.1 
10.9 
11.6 
12.3 
13.1 
13.9 
14.7 
15.6 
16.7 
17.8 
19.2 
15 
10.0 
10.7 
11.5 
12.2 
13.0 
13.8 
14.6 
15.5 
16.5 
17.7 
19.1 
18 
9.8 
10.6 
11.3 
12.0 
12.8 
13.6 
14.4 
15.4 
16.4 
17.6 
19.0 
22 
9.6 
10.3 
11.1 
11.8 
12.6 
13.4 
14.2 
15.2 
16.2 
17.4 
18.8 
26 
9.3 
10.1 
10.8 
11.6 
12.4 
13.2 
14.0 
15.0 
16.0 
17.2 
18.6 
28 
9.2 
10.0 
10.7 
11.5 
12.3 
13.1 
13.9 
14.9 
15.9 
17.1 
18.5 
 
 
EQUILIBRIUM MOISTURE CONTENT FOR PEAS (Modified Henderson) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
9.3 
10.4 
11.5 
12.6 
13.7 
14.9 
16.2 
17.6 
19.1 
20.8 
22.7 
2 
9.2 
10.2 
11.3 
12.4 
13.5 
14.7 
15.9 
17.3 
18.8 
20.4 
22.4 
5 
9.0 
10.1 
11.1 
12.2 
13.3 
14.5 
15.7 
17.1 
18.5 
20.2 
22.2 
8 
8.9 
9.9 
11.0 
12.1 
13.2 
14.3 
15.6 
16.9 
18.3 
20.0 
21.9 
10 
8.8 
9.9 
10.9 
12.0 
13.1 
14.2 
15.4 
16.8 
18.2 
19.8 
21.8 
13 
8.7 
9.7 
10.8 
11.8 
12.9 
14.1 
15.3 
16.6 
18.0 
19.6 
21.5 
15 
8.7 
9.7 
10.7 
11.7 
12.8 
13.9 
15.1 
16.4 
17.9 
19.5 
21.4 
18 
8.6 
9.6 
10.6 
11.6 
12.7 
13.8 
15.0 
16.3 
17.7 
19.3 
21.2 
22 
8.4 
9.4 
10.4 
11.4 
12.5 
13.6 
14.8 
16.0 
17.4 
19.0 
20.9 
26 
8.3 
9.3 
10.2 
11.3 
12.3 
13.4 
14.5 
15.8 
17.2 
18.7 
20.6 
28 
8.2 
9.2 
10.2 
11.2 
12.2 
13.3 
14.4 
15.7 
17.1 
18.6 
20.5 
 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR OATS (Modified Oswin) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
10.2 
10.7 
11.2 
11.8 
12.3 
12.9 
13.5 
14.1 
14.8 
15.7 
16.7 
2 
9.8 
10.3 
10.9 
11.4 
11.9 
12.5 
13.1 
13.7 
14.5 
15.3 
16.4 
5 
9.6 
10.1 
10.6 
11.1 
11.7 
12.2 
12.8 
13.5 
14.2 
15.1 
16.2 
8 
9.3 
9.8 
10.3 
10.9 
11.4 
12.0 
12.6 
13.3 
14.0 
14.9 
15.9 
10 
9.1 
9.7 
10.2 
10.7 
11.3 
11.8 
12.4 
13.1 
13.9 
14.7 
15.8 
13 
8.9 
9.4 
10.0 
10.5 
11.0 
11.6 
12.2 
12.9 
13.7 
14.5 
15.6 
15 
8.8 
9.3 
9.8 
10.3 
10.9 
11.5 
12.1 
12.8 
13.5 
14.4 
15.5 
18 
8.5 
9.1 
9.6 
10.1 
10.7 
11.3 
11.9 
12.6 
13.3 
14.2 
15.3 
22 
8.3 
8.8 
9.3 
9.9 
10.4 
11.0 
11.6 
12.3 
13.1 
14.0 
15.1 
26 
8.0 
8.6 
9.1 
9.6 
10.2 
10.8 
11.4 
12.1 
12.9 
13.8 
14.8 
28 
7.9 
8.4 
9.0 
9.5 
10.1 
10.7 
11.3 
12.0 
12.8 
13.7 
14.7 
 
EQUILIBRIUM MOISTURE CONTENT FOR CANOLA/RAPESEED (Modified Henderson) 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
6.7 
7.5 
8.2 
8.9 
9.7 
10.5 
11.3 
12.2 
13.2 
14.3 
15.7 
2 
6.4 
7.0 
7.7 
8.4 
9.1 
9.9 
10.7 
11.6 
12.5 
13.6 
14.9 
5 
6.1 
6.8 
7.4 
8.1 
8.8 
9.5 
10.3 
11.1 
12.0 
13.1 
14.3 
8 
5.9 
6.5 
7.1 
7.8 
8.5 
9.2 
9.9 
10.7 
11.6 
12.6 
13.8 
10 
5.7 
6.3 
7.0 
7.6 
8.3 
8.9 
9.7 
10.5 
11.3 
12.3 
13.5 
13 
5.5 
6.1 
6.7 
7.3 
8.0 
8.6 
9.4 
10.1 
11.0 
11.9 
13.1 
15 
5.4 
6.0 
6.6 
7.2 
7.8 
8.5 
9.2 
9.9 
10.7 
11.7 
12.8 
18 
5.2 
5.8 
6.4 
7.0 
7.6 
8.2 
8.9 
9.6 
10.4 
11.3 
12.4 
22 
5.0 
5.6 
6.1 
6.7 
7.3 
7.9 
8.5 
9.3 
10.0 
10.9 
12.0 
26 
4.8 
5.4 
5.9 
6.5 
7.0 
7.6 
8.2 
8.9 
9.7 
10.5 
11.6 
28 
4.8 
5.3 
5.8 
6.3 
6.9 
7.5 
8.1 
8.8 
9.5 
10.4 
11.4 
 
 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR LENTILS (Modified Oswin) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
9.3 
10.3 
11.2 
12.3 
13.4 
14.6 
16.0 
17.6 
19.5 
21.9 
25.0 
2 
9.1 
10.0 
11.0 
12.0 
13.1 
14.3 
15.7 
17.3 
19.1 
21.5 
24.5 
5 
9.0 
9.9 
10.8 
11.8 
12.9 
14.1 
15.4 
17.0 
18.8 
21.1 
24.2 
8 
8.8 
9.7 
10.6 
11.6 
12.7 
13.9 
15.2 
16.7 
18.5 
20.8 
23.8 
10 
8.7 
9.6 
10.5 
11.5 
12.5 
13.7 
15.0 
16.5 
18.3 
20.6 
23.6 
13 
8.5 
9.4 
10.3 
11.3 
12.3 
13.5 
14.8 
16.3 
18.0 
20.3 
23.2 
15 
8.4 
9.3 
10.2 
11.1 
12.2 
13.3 
14.6 
16.1 
17.8 
20.1 
23.0 
18 
8.3 
9.1 
10.0 
10.9 
12.0 
13.1 
14.3 
15.8 
17.5 
19.7 
22.6 
22 
8.1 
8.9 
9.7 
10.7 
11.7 
12.8 
14.0 
15.4 
17.1 
19.3 
22.1 
26 
7.8 
8.6 
9.5 
10.4 
11.4 
12.4 
13.6 
15.0 
16.7 
18.8 
21.6 
28 
7.7 
8.5 
9.4 
10.3 
11.2 
12.3 
13.5 
14.9 
16.5 
18.6 
21.4 
 
 
EQUILIBRIUM MOISTURE CONTENT FOR RED LENTILS (Modified Halsey) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
8.9 
9.5 
10.0 
10.6 
11.2 
12.0 
12.8 
13.8 
15.0 
16.5 
18.6 
2 
8.8 
9.3 
9.8 
10.4 
11.0 
11.8 
12.6 
13.5 
14.7 
16.2 
18.3 
5 
8.7 
9.2 
9.7 
10.3 
10.9 
11.6 
12.4 
13.4 
14.5 
16.0 
18.0 
8 
8.5 
9.0 
9.6 
10.1 
10.7 
11.4 
12.2 
13.2 
14.3 
15.8 
17.8 
10 
8.5 
8.9 
9.5 
10.0 
10.6 
11.3 
12.1 
13.1 
14.2 
15.7 
17.7 
13 
8.3 
8.8 
9.3 
9.9 
10.5 
11.2 
12.0 
12.9 
14.0 
15.5 
17.4 
15 
8.3 
8.7 
9.3 
9.8 
10.4 
11.1 
11.9 
12.8 
13.9 
15.3 
17.3 
18 
8.2 
8.6 
9.1 
9.7 
10.3 
10.9 
11.7 
12.6 
13.7 
15.1 
17.1 
22 
8.0 
8.5 
9.0 
9.5 
10.1 
10.7 
11.5 
12.4 
13.5 
14.9 
16.8 
26 
7.9 
8.3 
8.8 
9.3 
9.9 
10.6 
11.3 
12.2 
13.3 
14.6 
16.5 
28 
7.8 
8.2 
8.7 
9.2 
9.8 
10.5 
11.2 
12.1 
13.1 
14.5 
16.4 
 
 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR SOYBEANS (Modified Halsey) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
7.0 
7.6 
8.3 
9.1 
10.0 
11.0 
12.2 
13.6 
15.5 
17.9 
21.4 
2 
6.9 
7.5 
8.2 
8.9 
9.8 
10.8 
12.0 
13.5 
15.3 
17.7 
21.1 
5 
6.8 
7.4 
8.1 
8.9 
9.7 
10.7 
11.9 
13.3 
15.1 
17.5 
20.9 
8 
6.7 
7.3 
8.0 
8.8 
9.6 
10.6 
11.8 
13.2 
15.0 
17.4 
20.8 
10 
6.7 
7.3 
8.0 
8.7 
9.6 
10.5 
11.7 
13.1 
14.9 
17.3 
20.6 
13 
6.6 
7.2 
7.9 
8.6 
9.5 
10.4 
11.6 
13.0 
14.8 
17.1 
20.5 
15 
6.6 
7.2 
7.8 
8.6 
9.4 
10.4 
11.5 
12.9 
14.7 
17.0 
20.3 
18 
6.5 
7.1 
7.7 
8.5 
9.3 
10.3 
11.4 
12.8 
14.5 
16.9 
20.2 
22 
6.4 
7.0 
7.6 
8.4 
9.2 
10.1 
11.2 
12.6 
14.3 
16.6 
19.9 
26 
6.3 
6.9 
7.5 
8.2 
9.0 
10.0 
11.1 
12.5 
14.2 
16.4 
19.7 
28 
6.3 
6.8 
7.5 
8.2 
9.0 
9.9 
11.0 
12.4 
14.1 
16.3 
19.6 
 
 
EQUILIBRIUM MOISTURE CONTENT FOR FLAX (Modified Henderson/Chung-Pfost) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
7.4 
8.0 
8.5 
9.0 
9.5 
10.0 
10.6 
11.2 
11.9 
12.7 
13.6 
2 
7.1 
7.6 
8.1 
8.6 
9.1 
9.7 
10.2 
10.8 
11.5 
12.3 
13.2 
5 
6.9 
7.4 
7.9 
8.4 
8.9 
9.4 
10.0 
10.6 
11.2 
12.0 
12.9 
8 
6.7 
7.2 
7.7 
8.2 
8.7 
9.2 
9.7 
10.3 
11.0 
11.8 
12.7 
10 
6.6 
7.1 
7.5 
8.0 
8.5 
9.0 
9.6 
10.2 
10.8 
11.6 
12.5 
13 
6.4 
6.9 
7.3 
7.8 
8.3 
8.8 
9.4 
10.0 
10.6 
11.4 
12.3 
15 
6.3 
6.7 
7.2 
7.7 
8.2 
8.7 
9.3 
9.8 
10.5 
11.2 
12.1 
18 
6.1 
6.6 
7.0 
7.5 
8.0 
8.5 
9.1 
9.6 
10.3 
11.0 
11.9 
22 
5.9 
6.4 
6.8 
7.3 
7.8 
8.3 
8.8 
9.4 
10.0 
10.8 
11.7 
26 
5.7 
6.2 
6.6 
7.1 
7.6 
8.1 
8.6 
9.2 
9.8 
10.5 
11.4 
28 
5.6 
6.1 
6.5 
7.0 
7.5 
8.0 
8.5 
9.1 
9.7 
10.4 
11.3 
 
 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR SUNFLOWER SEEDS (Modified Halsey) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
5.5 
5.9 
6.3 
6.7 
7.3 
7.9 
8.5 
9.4 
10.4 
11.7 
13.6 
2 
5.3 
5.7 
6.1 
6.6 
7.1 
7.6 
8.3 
9.1 
10.1 
11.4 
13.3 
5 
5.2 
5.6 
6.0 
6.4 
6.9 
7.5 
8.1 
8.9 
9.9 
11.2 
13.0 
8 
5.1 
5.5 
5.8 
6.3 
6.8 
7.3 
8.0 
8.7 
9.7 
11.0 
12.7 
10 
5.0 
5.4 
5.8 
6.2 
6.7 
7.2 
7.9 
8.6 
9.6 
10.8 
12.6 
13 
4.9 
5.3 
5.6 
6.1 
6.5 
7.1 
7.7 
8.4 
9.4 
10.6 
12.3 
15 
4.8 
5.2 
5.6 
6.0 
6.4 
7.0 
7.6 
8.3 
9.2 
10.4 
12.2 
18 
4.7 
5.1 
5.4 
5.8 
6.3 
6.8 
7.4 
8.1 
9.0 
10.2 
11.9 
22 
4.6 
4.9 
5.3 
5.7 
6.1 
6.6 
7.2 
7.9 
8.8 
10.0 
11.6 
26 
4.5 
4.8 
5.1 
5.5 
5.9 
6.4 
7.0 
7.7 
8.6 
9.7 
11.3 
28 
4.4 
4.7 
5.1 
5.4 
5.9 
6.3 
6.9 
7.6 
8.4 
9.6 
11.1 
 
 
EQUILIBRIUM MOISTURE CONTENT FOR SUNFLOWER HULLS (Modified Halsey) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
9.2 
9.9 
10.6 
11.4 
12.3 
13.4 
14.6 
16.0 
17.8 
20.1 
23.3 
2 
8.7 
9.3 
10.1 
10.8 
11.7 
12.7 
13.9 
15.3 
17.0 
19.2 
22.3 
5 
8.3 
9.0 
9.7 
10.4 
11.3 
12.2 
13.3 
14.7 
16.3 
18.5 
21.5 
8 
8.0 
8.6 
9.3 
10.0 
10.8 
11.7 
12.8 
14.1 
15.7 
17.8 
20.7 
10 
7.8 
8.4 
9.0 
9.7 
10.5 
11.4 
12.5 
13.8 
15.3 
17.4 
20.2 
13 
7.5 
8.0 
8.7 
9.3 
10.1 
11.0 
12.0 
13.2 
14.8 
16.7 
19.5 
15 
7.3 
7.8 
8.4 
9.1 
9.8 
10.7 
11.7 
12.9 
14.4 
16.3 
19.1 
18 
7.0 
7.5 
8.1 
8.7 
9.4 
10.3 
11.2 
12.4 
13.8 
15.7 
18.4 
22 
6.6 
7.1 
7.6 
8.2 
8.9 
9.7 
10.6 
11.8 
13.1 
14.9 
17.5 
26 
6.2 
6.7 
7.2 
7.8 
8.5 
9.2 
10.1 
11.1 
12.5 
14.2 
16.6 
28 
6.0 
6.5 
7.0 
7.6 
8.2 
9.0 
9.8 
10.8 
12.1 
13.8 
16.2 
 
 
 
 
 
 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
EQUILIBRIUM MOISTURE CONTENT FOR SUNFLOWER KERNELS (Modified Halsey) 
 
Temp 
Relative Humidity (%) 
(°C) 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
-2 
4.3 
4.6 
4.9 
5.3 
5.7 
6.2 
6.8 
7.4 
8.3 
9.4 
11.0 
2 
4.1 
4.4 
4.8 
5.1 
5.5 
6.0 
6.6 
7.2 
8.0 
9.1 
10.6 
5 
4.0 
4.3 
4.7 
5.0 
5.4 
5.9 
6.4 
7.0 
7.9 
8.9 
10.4 
8 
4.0 
4.2 
4.6 
4.9 
5.3 
5.7 
6.3 
6.9 
7.7 
8.7 
10.2 
10 
3.9 
4.2 
4.5 
4.8 
5.2 
5.7 
6.2 
6.8 
7.6 
8.6 
10.0 
13 
3.8 
4.1 
4.4 
4.7 
5.1 
5.5 
6.0 
6.6 
7.4 
8.4 
9.8 
15 
3.7 
4.0 
4.3 
4.6 
5.0 
5.4 
5.9 
6.5 
7.3 
8.3 
9.7 
18 
3.7 
3.9 
4.2 
4.5 
4.9 
5.3 
5.8 
6.4 
7.1 
8.1 
9.5 
22 
3.5 
3.8 
4.1 
4.4 
4.8 
5.2 
5.6 
6.2 
6.9 
7.9 
9.2 
26 
3.4 
3.7 
4.0 
4.3 
4.6 
5.0 
5.5 
6.0 
6.7 
7.6 
8.9 
28 
3.4 
3.6 
3.9 
4.2 
4.5 
4.9 
5.4 
5.9 
6.6 
7.5 
8.8 
 
If you have any questions about the information presented in this document, please contact Dr. Joy 
Agnew at PAMI. Email jagnew@pami.ca or phone (306) 682-5033 ext 280.  
 
Reference information 
 
BARLEY 
- 
Model: Chung Pfost 
- 
Source: American Society of Agricultural and Biological Engineers (2012). ASABE Standard 
D245.5. Moisture Relationships of Plant-Based Agricultural Products. 
CANOLA/RAPESEED 
- 
Model: Modified Henderson 
- 
Source: S. Sokhansanj, W. Zhijie, D. Jayas, T. Kameoka (1986) Equilibrium Relative Humidity-
Moisture Content of Rapeseed (Canola) from 5°C to 25°C. 
 
DURUM WHEAT 
- 
Model: Modified Oswin 
- 
Source: American Society of Agricultural and Biological Engineers (2012). ASABE Standard 
D245.5. Moisture Relationships of Plant-Based Agricultural Products. 
 
FLAX 
- 
Varieties: Linnot, Dufferin, Mcgregor, Norlin, Norman (EMC chart is an average of all varieties) 
- 
Models: Average of Modified Henderson and Modified Chung-Pfost (EMC chart is an average of 
both models) 
- 
Source: G. Mazza, D.S Jayas, N.D.G. White. (1990) Moisture Sorption Isotherms of Flax Seed. 
 
HARD RED SPRING WHEAT 
- 
Variety: Sinton 
- 
Model: Modified Chung-Pfost 
- 
Source: American Society of Agricultural and Biological Engineers (2012). ASABE Standard 
D245.5. Moisture Relationships of Plant-Based Agricultural Products. 

 
 
 
 
Prairie Agricultural Machinery Institute 
Box 1150, 2215 – 8th Ave., Humboldt, Saskatchewan   S0K 2A0    Canada 
306-682-5033  
1-800-567-7264  Fax: 306-682-5080  
www.pami.ca 
HARD RED WINTER WHEAT 
- 
Varieties: Waldron, Napayo (EMC chart is an average of both varieties) 
- 
Model: Modified Oswin 
- 
Source: American Society of Agricultural and Biological Engineers (2012). ASABE Standard 
D245.5. Moisture Relationships of Plant-Based Agricultural Products. 
LENTILS 
- 
Model: Modified Oswin 
- 
Source: Nikolay D. Menkov. (2000). Moisture Sorption Isotherms of Lentil Seeds at Several 
Temperatures. 
 
OATS 
- 
Varieties: Dumont, Newman (EMC chart is an average of both varieties) 
- 
Model: Modified Chung-Pfost 
- 
Source: D.S. Jayas, G. Mazza. (1993) Comparison of Five, Three-Parameter Equations for the 
Description of Adsorption Data of Oats.  
 
PEAS 
- 
Model: Modified Henderson 
- 
Source: Chiachung Chen. (2002). Moisture Sorption Isotherms of Pea Seeds. 
 
RED LENTILS 
- 
Varieties: Robin, Redberry, Blaze (EMC chart is an average of all varieties) 
- 
Model: Modified Halsey 
- 
Source: S. Cenkowski, J. Paliwal, S. Arntfield, M. Gervais. (2015) Sorption Characteristics of Red 
Lentils as Affected by Postharvest Conditions.  
 
SOYBEANS 
- 
Varieties: Essex, Britain (EMC chart is an average of both varieties) 
- 
Model: Modified Halsey 
- 
Source: Z. Yang, E. Zhu, Z. Zhu. (2012). Moisture Sorption Isotherms and Net Isostatic Heats of 
Sorption of Green Soybeans.  
 
SUNFLOWER SEEDS/HULL/KERNEL 
- 
Model: Modified Halsey 
- 
Source: G. Mazza, D.S. Jayas. (1991). Equilibrium Moisture Characteristics of Sunflower Seeds, 
Hulls, and Kernels.  

 
Equilibrium Moisture Content for Grains 
Implications for drying:  
 Grain will eventually reach the moisture levels shown in the tables when exposed to the 
corresponding temperature and humidity levels for long periods of time. This can occur 
in the field or in the top layers of a low-temperature bin dryer. 
 Drying time will depend on the airflow rate through grain, which in turn depends on the 
depth of grain in a bin. The minimum drying rate for natural air drying is 1 cfm/bu, but this 
can take up to a month to dry the top layer depending on the grain and air conditions--
during which time spoilage can occur. 
Implications for storage:  
 The air space between kernels in a bin of corn will have the humidity indicated at the 
corresponding moisture and temperature. For example, 15% corn at 60 degrees will 
generate a relative humidity in the air space between kernels of 70%, but when cooled to 
45 degrees will have a relative humidity of 65%. 
 Mold growth is suppressed during storage when the environment is maintained at a 
relative humidity level of 65% or lower. 
Table 1. Equilibrium moisture content of yellow corn (%wb) at different temperature and relative 
humidity levels. 
 
Temp. 
Relative Humidity (%) 
10 
20 
30 
40
50
60
65
70 
80
90
F 
Equilibrium moisture content, %wb 
35 
6.5 
8.6 
10.3 
11.8
13.3
14.8
15.7
16.6 
18.7
21.7
40 
6.2 
8.3 
9.9 
11.5
12.9
14.5
15.3
16.2 
18.3
21.3
50 
5.7 
7.8 
9.4 
10.9
12.3
13.8
14.7
15.5 
17.6
20.5
60 
5.3 
7.3 
8.9 
10.3
11.8
13.3
14.1
15.0 
17.0
19.9
70 
4.9 
6.9 
8.4 
9.9
11.3
12.8
13.6
14.4 
16.4
19.4
80 
4.6 
6.5 
8.0 
9.4
10.8
12.3
13.1
14.0 
16.0
18.8
90 
4.2 
6.1 
7.7 
9.1
10.5
11.9
12.7
13.5 
15.5
18.4
Source: ASAE Data D245.4 / Average of two prediction equations. 
 
Prepared by:  
Sam McNeill, PhD, PE 
Extension Agricultural Engineer 
UK Research and Education Center 
Princeton, KY  42445-0469 
Ph: (270) 365 - 7541 x 213 
Email: sam.mcneill@uky.edu 

 
 
Table 2. Equilibrium moisture content of soybeans (%wb) at different temperature and relative 
humidity levels. 
 
Temperature 
Relative Humidity (%) 
10 
20 
30 
40
50
60
65
70 
80 
90
C 
    F 
Equilibrium moisture content, %wb 
1.7 
35 
4.2 
5.3 
6.5 
7.8
9.4
11.5
12.8
14.4 
19.1 
28.9
4.4 
40 
4.1 
5.3 
6.4 
7.7
9.3
11.3
12.6
14.2 
18.9 
28.7
10 
50 
4.0 
5.2 
6.3 
7.6
9.1
11.1
12.4
14.0 
18.6 
28.2
16 
60 
4.0 
5.1 
6.2 
7.4
8.9
10.9
12.2
13.7 
18.3 
27.8
21 
70 
3.9 
5.0 
6.1 
7.3
8.8
10.7
11.9
13.5 
17.9 
27.3
25 
77 
3.8 
4.9 
6.0 
7.2
8.6
10.6
11.8
13.3 
17.7 
27.0
32 
90 
3.7 
4.8 
5.8 
7.0
8.4
10.3
11.5
13.0 
17.3 
26.5
Source: ASAE Data D245.5 / modified-Halsey equation. 
 
 
Table 3. Equilibrium moisture content of soft red winter wheat (%wb) at different temperature 
and relative humidity levels. 
 
Temperature  
Relative Humidity (%) 
10 
20 
30 
40
50
60
65
70
80 
90
C 
F 
Equilibrium moisture content, %wb 
1.7 
35 
7.3 
8.9 
10.2 
11.3
12.3
13.4
14.0
14.7
16.1 
18.2
4.4 
40 
7.1 
8.7 
10.0 
11.1
12.1
13.2
13.8
14.4
15.9 
18.0
10 
50 
6.8 
8.4 
9.6 
10.7
11.8
12.9
13.4
14.1
15.5 
17.6
16 
60 
6.5 
8.1 
9.3 
10.4
11.4
12.5
13.1
13.7
15.1 
17.2
21 
70 
6.2 
7.8 
9.0 
10.1
11.1
12.2
12.8
13.4
14.8 
16.9
25 
77 
6.0 
7.5 
8.7 
9.8
10.9
11.9
12.5
13.1
14.5 
16.6
32 
90 
5.8 
7.3 
8.5 
9.6
10.6
11.6
12.2
12.8
14.2 
16.3
Source: ASAE Data D245.4 / Average of two prediction equations. 
 
 
 
 
 
Prepared by:  
 
Sam McNeill, PhD, PE 
Extension Agricultural Engineer 
UK Research and Education Center 
Princeton, KY  42445-0469 
 
Ph: (270) 365 - 7541 x 213 
Email: sam.mcneill@uky.edu