Specifications

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If noise still present, re-attach cables and wrap unit in tin foil, leave fan openings open.

If still noisy, rent vehicle and run Bloodhound from rented vehicle away from platform.

Sample Flow Rate

Troubleshooting

There are three items on the Real Time Data screen of Gas Chart that tell the user

about the flow properties. These 3 things are have a relational operation to each other.

Vac - tells the user how much vacuum is being pulled on the sample line. If it is a high

negative number then there is a high vacuum, if it is a very low negative number then

there is no draw on the line. If above -200 the Bloodhound will turn the sample motor

off (see % motor power) until the occlusion in the line is cleared. The pump has the

ability to pull up to -600 mmHg on the line, but is programmed to not let it get that high

because if there is not a good flow in the line at -200 mmHG then something is

blocking the line so it is limited to -200.

Percent Motor Power - This tells the user how much energy the Bloodhound is giving

the sample motor. A higher number means a higher voltage is being sent to the

sample motor. Typically if below 100, there should not be any problems; if above 100

the motor may be going out or there is an occlusion building in the line. 200% (12 volts

DC) is maximum. If allowed to build up to 200, the motor % power will cycle back to 0

% power to give the motor a rest and cool off as it starts to build again. Sometimes

this will allow the motor to restart if it is marginal. Generally a higher power will draw a

higher vacuum on the line and a higher flow rate (LPH). A lower power will reduce the

vacuum and flow rate.

LPH (liters per hour) flow - The flowmeter in the unit monitors the flow through the

system. The Bloodhound will change the motor power up and down until a flow rate of

55 to 645 LPH is obtained . If the line starts to get plugged up, the power to the motor

is increased to maintain the flow. This results in a higher vacuum. If the line is

disconnected from the Bloodhound the vacuum will drop to almost zero, and the flow

rate will increase until the motor power is once again adjusted to compensate for the

pressure change.

If the pump motor is bad, as the power increases, the motor does not turn, the vac and

flow are low, and when the power reaches 200, it cycles back down to 0 and tries

again. This can be tested momentarily by connecting a clean piece of tubing to the

inlet port and blowing into it. If the flow meter shows a flow briefly, then the motor is

not running.

If the pump is bad, there would be no vacuum on the inlet port and the vacuum and

flow would be low or missing.

If the flowmeter is bad, you would see the vacuum build up and then suddenly drop as

the percent motor increased and then dropped to cycle again. To overcome a bad

flowmeter, set Register 10 to something like 80. This will set the pump to a static

power setting and bypass the flow meter. This allows the Bloodhound to finish the job.

When Register 10 is set to a motor power percent number (1 to 199), the sample motor

is on a constant setting and the flowmeter may change but the power to the motor will

not. In addition, the flow rate alarms are defeated. Since flow rate does not effect the

sensors, this setting is ok for finishing a job.

If the vacuum sensor is bad, you would see good flow and percent motor but an odd

vacuum. This can be tested by placing a finger over the inlet. If the vacuum suddenly

increases the sensor is ok, if not then the vacuum sensor is bad.

One interesting thing is when there is a lot of water built up in the line you will see the

flow/vac/power cycle up and down as the water allows for air to burp in the line.