Issue Date: November 22, 1995
Revision Date: February 6, 2015
Purpora Engineering, Inc.
(originally listed by Alert Technologies, Inc.)
Alert Model 2000 In-Tank Mass
Measurement Probe System
(Mass Buoyancy Probe)
AUTOMATIC TANK GAUGING METHOD
||Leak rate of 0.2 gph with PD = 95.4% and
PFA = 4.6% (calculated based on a 1-hour test).
A tank system should not be
declared tight if the test result indicates a loss or gain that equals or
exceeds this threshold.
||Gasoline, diesel, aviation fuel, fuel oil
#4, waste oil.
||Maximum of 15,000 gallons.
Tank must be between 50 and 95% full.
||Minimum of 15 hours between delivery and
There must be no delivery during waiting time.
||Minimum of 2 hours.
Test data are acquired and recorded by system's computer.
Leak rate is calculated from data determined to be valid by statistical
There must be no dispensing or delivery during test.
||Product measurement not required.
System measures product mass (which is not affected by temperature)
instead of product volume.
||Must be used to detect water ingress.
Minimum detectable water level in the tank is 0.175 inch (0.27 inch for
Minimum detectable change in water level is 0.088 inch (0.031 inch for
||Mass measurement probe and water sensor
must be checked and, if necessary, calibrated in accordance with
Not evaluated using manifolded
tank systems. Therefore, this certification is only applicable when there is
a probe used in each tank and the siphon is broken during testing.
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 undetected.
EPA leak detection regulations require testing of
the portion of the tank system which routinely contains product.
System is battery operated and does not automatically generate a hard copy
of the leak test result. However, a hard copy of the results can be
obtained by transfer of data to another unit (see manufacturer's
instructions for further details).
System is not equipped with any alarms (e.g. high water alarm, or failed
leak test alarm).
does not support test results if the technician does not hold a current
Alert Technologies certification when the test is performed.
Recertification is required by the manufacturer every two years.
Purpora Engineering Inc.
Evaluator: Midwest Research Institute
658 North Progress Drive
Saukville, WI 53080
of Evaluation: 03/11/91
Tel: (262) 536-4081