Issue Date: November 22, 1995
Revision Date: March 16, 1998
(Mass Buoyancy Probe)
AUTOMATIC TANK GAUGING METHOD
||Leak rate of 0.2
gph with PD = 97.9% and PFA = 1.1%.
A tank system should not be declared tight if the test result indicates a
loss or gain that equals or exceeds this threshold.
||Maximum of 15,000
Tank must be between 50 and 95% full.
||Minimum of 7
hours between delivery and testing.
There must be no dispensing or delivery during waiting time.
||Minimum of 5
hours, 30 minutes.
Test data are acquired and recorded by system's computer.
Leak rate is calculated from average of subsets of all collected
There must be no dispensing or delivery during test.
product is obtained by a single moving quartz crystal temperature sensor.
||Must be used to
detect water ingress.
Minimum detectable water level in the tank is 0.253 inch.
Minimum detectable change in water level is 0.029 inch.
sensor and probe must be checked and, if necessary, calibrated in
accordance with manufacturer's instructions.
using manifolded tank systems. Therefore, this certification is only
applicable when there is a probe used in each tank and the siphon is broken
Tests only portion of tank containing product.
As product level is lowered, leak rate in a leaking tank decreases (due to
lower head pressure).
Consistent testing at low levels could allow a leak to remain
EPA leak detection regulations require testing of the portion of the tank
system which routinely contains product.
Midwest Research Institute
1201 - 2900
011-32-3-03/645 27 90