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UST Program - LG 113

UST Programs - LG 113

Issue Date: November 22, 1995
Revision Date: November 14, 1997

Universal Sensors and Devices, Inc.

(Magnetostrictive Probe)


Certification Leak rate of 0.2 gph with PD = 96.6% and PFA = 3.4%.
Leak Threshold 0.1 gph. 
A tank system should not be declared tight if the test result indicates a loss or gain that equals or exceeds this threshold.
Applicability Gasoline, diesel, aviation fuel. 
Other liquids with known coefficients of expansion and density may be tested after consultation with the manufacturer.
Tank Capacity Maximum of 15,000 gallons. 
Tank must be minimum 90% full.
Waiting Time Minimum of 8 hours between delivery and testing. 
None between dispensing and testing. 
There must be no delivery during waiting time.
Test Period Minimum of 6 hours. 
Test data are acquired and recorded by a microprocessor. 
Leak rate is calculated from average of subsets of all collected data. 
There must be no dispensing or delivery during test.
Temperature Average for product is determined by a minimum of 5 resistance temperature detectors (RTDs).
Water Sensor Must be used to detect water ingress. 
Minimum detectable water level in the tank is 0.83 inch. 
Minimum detectable water level change is 0.0116 inch.
Calibration RTDs and probe must be checked and, if necessary, calibrated in accordance with manufacturer's instructions.

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.

California regulations require at least one test per month after routine product delivery or when the tank is filled to within 10% of the highest operating level of previous month.


Universal Sensors and Devices, Inc.

Evaluator:  Ken Wilcox Associates

9205 Alabama Ave., Unit C

Tel:  (816) 443-2494

Chatsworth, CA  91311

Date of Evaluation:  08/20/93

Tel:  (800) 899-7121, (818) 998-7121


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