Smoke Damage >> How To DIY How To Repair A House Damaged By Smoke

Effects on Smoke on Functional Circuits SNL also tested complete and functional circuit boards for their susceptibility to damage from smoke [18]. These boards contained five functional circuits that could be energized and How To DIY How To Repair A House Damaged By Smoke monitored during smoke exposure. Each circuit was present twice on each board, built with either surface-mount technology (SMT) or pin through hole (PTH) components. 

Half of the boards tested were How To DIY How To Repair A House Damaged By Smoke protected with a polyurethane conformal coating. The circuits included thefollowing: High-Voltage Low-Current (HVLC): This high-resistance series of capacitor-resistorpairs was subject to a 300 Vdc bias. The nominal current was 6 μA. Within the networkitself, the potential difference between any two adjacent copper traces was 60 Vdc. 

High-Current Low-Voltage (HCLV): This circuit contained a number of How To DIY How To Repair A House Damaged By Smoke resistors andcapacitors in parallel. A constant-current power supply adjusted the applied voltage tomaintain 1 A through the nominal 1.43 Ω. High-Speed Digital (HSD): This circuit simply connected a series of NAND logic gates.

While powered, a 5 V, 20 ns input pulse was applied to the first gate, and the output ofthe final gate was monitored. Increases in the rise, How To DIY How To Repair A House Damaged By Smoke fall and delay (relative to input) timesof the output square pulse all indicate degradation of a circuit. High-Frequency Low-Pass Filter (HFLPF): a system of inductors and capacitorsconfigured to attenuate high frequency input signals. 

Before and after exposure, thefilters were tested for signal attenuation from 50 MHz to 1 GHz. During exposure, theywere tested for: attenuation at 50 MHz, 250 MHz and How To DIY How To Repair A House Damaged By Smoke the frequencies at whichattenuation reached -3 and -40 dB. High-Frequency Transmission Line (HFTL): this circuit was two adjacent PCB coppertraces, designed to exhibit 50 Ω impedance. 

It is expected that a small amount of a signalon one line will be transmitted to the other. This behavior, How To DIY How To Repair A House Damaged By Smoke referred to as coupling, isfrequency dependent and is expected to increase with the conductivity between the lines.During exposure, coupling between the lines was measured at 50 MHz, 500 MHz and 1GHz. 

Pre- and post-exposure tests added measurements of coupling with the second lineconnected in a reversed configuration.In addition to the functional circuits, additional components on the board were tested for leakagecurrents before, during and How To DIY How To Repair A House Damaged By Smoke after exposure. Further leakage current measurements wereperformed using an interdigitated comb test board. 

Each board had four distinct comb patternsand during exposure, two were biased with 5 Vdc and the other two with 30 Vdc.The tests used the standard exposure method, How To DIY How To Repair A House Damaged By Smoke with fuel loads of 3 g/m3, 25 g/m3and 50 g/m3heated with 50 kW/m2 and 25 kW/m2. Soot deposition was measured with two quartz crystalmicrobalances (QCM), one oriented vertically and the other oriented horizontally. 

The quantitiesdeposited and fuel burned are listed below in Table 2. Note that the 25 kW/m2heat fluxexposures caused smoldering of the fuel while the 50 kW/m2flux caused flaming. No direct measurements of corrosion were performed, How To DIY How To Repair A House Damaged By Smoke but visual inspection of componentsshowed that components made of reactive metals (such as nickel) had corroded significantlyafter the test.

The HVLC circuit showed susceptibility to smoke exposure. Resistance decreased noticeablywith smoke density and recovered somewhat after venting of the chamber. Conformal coatings were very effective at preventing or limiting resistance losses for all fuel loads. In this particular circuit, How To DIY How To Repair A House Damaged By Smoke the PCB traces were the most vulnerable to damage because they carried the highestpotential differences and were more closely spaced than the leads of attached components.

Because this vulnerability was independent of the types of components attached, there was noobserved difference between PTH and SMT.The HCLV circuit was largely insensitive to smoke. Because the circuit had a very low initial resistance, How To DIY How To Repair A House Damaged By Smoke the addition of weakly conductive alternate paths would have little impact. 

Theexception was the case of the bare (having no conformal coating) SMT board. In all of the medium and high fuel load tests, How To DIY How To Repair A House Damaged By Smoke the resistance of these circuits increased measurably (0.9 % -1.7 %) and did not recover after venting. This change is attributed to corrosion of contacts or solder joints. None of the changes in these tests represented a significant effect on systemperformance.

The HSD circuit was tested for its response to a 20 ns, +5 Vdc pulse by measuring the output risetime, fall time and delay. Changes in signal degradation due to differences in cable length makedirect comparison between pre-test results and in situ measurements invalid. However, How To DIY How To Repair A House Damaged By Smoke none ofthe circuits showed significant change in response to changing fuel loads or the presence ofconformal coatings. 

Previous work indicates that the highest fuel load used would have causedfailure due to circuit bridging in complementary metal-oxide semiconductor (CMOS) chips, How To DIY How To Repair A House Damaged By Smoke but that advanced Schottky transistor to transistor logic (FAST TTL), such as those in the HSD, areless sensitive.The HFLPF did not show any response to smoke. 

However, How To DIY How To Repair A House Damaged By Smoke active measurement duringexposure was performed with an input frequency (250 MHz) that would not be impacted bychanges in system capacitance due to debris (the expected failure mode). Post-test measurements over a wider range of frequencies showed no change from the pre-test condition.

It was expected that the most severe changes in capacitance would occur during exposure, How To DIY How To Repair A House Damaged By Smoke when the testing method would be unable to measure those changes.The HFTL circuit was tested to determine coupling between two adjacent lines. Coated boardsshowed no change in coupling during or after exposure. 

The bare board experienced a large (from -52 dB to -17 dB) increase in coupling of 50 MHz signals during exposure. Coupling on the bare board returned to pre-test values quickly after venting of the test chamber. At high frequencies (500 MHz and 1 GHz) coupling on the bare board actually decreased during smoke exposure and How To DIY How To Repair A House Damaged By Smoke returned to pre-test values after venting. 

Leakage current data are presented only for the PTH boards and the interdigitated comb; leakage data for other components in the methodology section were not reported. Resistance on the bareboards dropped as fuel load increased and How To DIY How To Repair A House Damaged By Smoke recovered somewhat after venting. 

Changes in the interdigitated comb were less consistent, but surface resistance generally decreased with increasing fuel loads and How To DIY How To Repair A House Damaged By Smoke partially recovered after venting. Results in Table 4 are presented inthe change of Log10(R) between pre-test values and average during smoke exposure.

Empowered Water Carpet Cleaning

Flood Water After a Disaster or Emergency When returning to your home after a hurricane or flood, be aware that flood water may contain sewage. Protect yourself and your family by following these steps:Inside the Home Keep children and Water Extraction Empowered Water Carpet Cleaning pets out of the affected area until cleanup has b  read more..

How To Hide An Aluminum Sliding Window With Wood

Drain deaerator and open inspection doors and trays. Drain all boiler feed pumps and lines.7. Drain condensate receiver tank. Open manhole on tank.8. Drain chemical feed pump barrels and dispose of chemicals in a safe manner.9. Drain water softener tank and brine receiver.10. Shut off valves to main  read more..

Secure Your Roof Against Hurricane Winds

During a hurricane, homes may be damaged or destroyed by high winds and high waves. Debris can break windows and doors, allowing high winds inside the home. In extreme storms, such as Hurricane Andrew, Wind Damage Secure Your Roof Against Hurricane Winds the force of the wind alone can cause weak places in your home to fail.    read more..

Basement Sealing

Basement sealing Insulation A properly insulated Basement Drying Basement Sealing can save you money on heating and provide a dry, comfortable living space. In most cases, a basement sealing with insulation installed on its exterior walls should be considered a conditioned space. 

Even in a hou  read more..

Pipe Leaks

Water Damage Pipe Leaks could be called the silent destroyer, there might be a water leak for days that goes unnoticed then squish you step into it with your stocking feet. But, you think, where did it come from, it’s fairly close to the kitchen sink. You open the cabinet and pull everything out from insid  read more..

Crime Scene Technician Certification

In 2008, Karen Evans, administrator of the Office of Government and Information Technology at the White House's Office of Management and Budget (OMB), wrote a memo to all government chief information officers that read, Crime Scene Cleanup Crime Scene Technician Certification in part: 

"The Government's reli  read more..

How To Paint Over Fire Damage On Drywall

The president of NFPA (National Fire Protection Association) today called for all nursing homes in the U.S. to be equipped with fire sprinklers, in the wake of two recent nursing home fires in Hartford and Nashville, Fire Damage How To Paint Over Fire Damage On Drywall where a total of 24 people died. (See NFPA's fact sheet on nursing home fire s  read more..

Learn Fire Damage Electronic Repair

Static and dynamic burn-in shall be performed at maximum recommended operating supply voltage @ TA = 125 C . Biasing conditions including the value of RL shall be selected to assure that the junction temperature shall not exceed Tj max specified for the device type.2/ See MIL-HDBK-1331: Parameters t  read more..

How To Get Rid Of Sewer Smells

In general, the TRS concentration was high from the noon to the evening, with several intermittent high peaks (Figure 4(D)). In fact, the shops and jewelers in the district were open late in the morning at 9:00 to 11:00; so low TRS emission could be observed in the early morning. After the shops wer  read more..

F5 Tornado Facts

As the cold pool elongates, repetitive storm growth on the downwind-moving, progressive part of the gust front comprises the derecho-producing convective system (red arc in bottom cross section of figure below, and Wind Damage F5 Tornado Facts on right side of plan view inset). 

Meanwh  read more..