Figure 5. Fill levels with allowance for expansion
Tank Capacity (gallons)	Tank Height (inches)	Maximum fill level (inches)
5,000	96	86
6,500	120	108
10,000	183	165
13,000	240	216
15,000	279	251
20,000	351	316
23,000	420	378
25,000	447	402
30,000	519	467
35,000	591	532

Most ambient temperature fluctuations during a 24 hour period will have very little effect on a full tank of fuel. The temperature of the fuel will probably remain close to an average of the ambient temperatures over 24 hours. However, fuel temperatures are apt to change to a greater extent over several weeks or months, when the weather changes from one season to another.

Figure 6 shows how changes in fuel temperature affects its volume. The volumes shown for 60 degrees F correspond to the capacities of standard Heatec tanks. The temperatures should be regarded as average temperatures over a period of 24 hours.

Figure 6. How fuel volumes (gallons) change with changes in fuel temperature
30 Deg F	40 Deg F	50 Deg F	60 Deg F	70 Deg F	80 Deg F	90 Deg F	100 Deg F
4,955	4,970	4,985	5,000	5,015	5,030	5,045	5,060
6,442	6,461	6,481	6,500	6,520	6,539	6,559	6,578
9,910	9,940	9,970	10,000	10,030	10,060	10,090	10,121
12,883	12,922	12,961	13,000	13,039	13,078	13,117	13,157
14,865	14,910	14,955	15,000	15,045	15,090	15,135	15,181
19,821	19,880	19,940	20,000	20,060	20,120	20,181	20,241
22,794	22,862	22,931	23,000	23,069	23,138	23,208	23,277
24,776	24,850	24,925	25,000	25,075	25,150	25,226	25,301
29,731	29,820	29,910	30,000	30,090	30,180	30,271	30,362
34,686	34,790	34,895	35,000	35,105	35,210	35,316	35,422

TROUBLESHOOTING TRANSMITTERS
Pockets of air or trash trapped in the pipe where the transmitter is connected to the tank will cause erratic level readings. When filling an empty tank be sure to bleed the pipe connection at the transmitter to avoid this problem. Also bleed the connection if the tank is refilled after it was drained below the 16-inch level.

INSTALLING A NEW TRANSMITTER
All new transmitters must be programmed at the Heatec factory using special Siemens software configured for Heatec tanks.

Only two settings can be reset in the field. One is the Full Scale Blind setting, which should be set according to the specific gravity of the fuel as explained earlier.

The other is the zero setting. This setting corrects for transmitter tilt. The transmitter is normally tilted upwards for easy reading when it is installed on the tank at Heatec. If you change this tilt, you should reset the zero setting according to instructions in the Siemens manual, under the heading 6.2.5 Zero Adjustment (Position Correction).