TECK TIP 13

HOW TO PROPERLY “QUICK CHECK” MULTI-RAM RDA IIIA

<< return to previous page

Use only the U-TECK “Quick Check” gas and Gas Flow Regulator provided by U-TECK. “Quick Check” gas is formulated specifically for testing Multi-RAM RDA IIIA instruments to ensure that the unit’s lowest level of response to combustible gas is at 10% LEL (Lowest Explosive Level) of methane.

NOTE: Do not check the operation of the unit by sampling the vapors from truck exhaust, gasoline, propane, a butane lighter, or acetylene. This can permanently damage the sensor and affect its accuracy. Also, do not use gas from other test kits such as the “C” Gas Test Kit (used formerly for testing B-Gas Indicators or Explosimeters). Only the special gas in the “Quick Check Kit” is suited for this application, and ensures proper instrument response to 10% LEL. Using only approved “Quick Check” gas also ensures that OSHA and manufacturer calibration requirements for testing gas detection instruments are met.

The calibration “Quick Check Kit” consists of one small lightweight steel cylinder of 5000 parts per million test gas (methane in air mixture), a valve to regulate gas flow, a hose with an adapter for applying gas to the instrument sensor, and a small screwdriver for adjustments if necessary.

A “quick check” of the instrument should be performed in a gas free atmosphere at the job site prior to “Testing, Purging, and Ventilating”, or as covered by other company practices.

Setting up the Multi-RAM RDA IIIA prior to a “Quick Check”

• Make sure the CMU power toggle switch is in the off position.
• Connect the plug from the remote sensing unit (RSU) into the receptacle provided on the back of the central monitoring unit (CMU) marked “sensor”.
• Connect the AC power cord into the corresponding receptacle on the back of the CMU.
• Connect the power cord into an appropriate 110 – 120 volt AC supply receptacle (either generator or commercial power source).
• Move the power toggle into the “on” position (in the direction of the word power)
• The entire system should now come on. The green status light on the RSU should be lit, as well as the amber status light on the CMU.
• The internal sensor at the end of the RSU needs to warm up slightly in order to sense combustible gases, and as it warms up the red light on the RSU should begin to flash, and the red light on the CMU should light. The alarm horns inside the RSU and CMU should also both begin to sound. When the sensor warms up sufficiently (usually within 30 seconds or so at normal room temperature), the flashing red light at the RSU should go out. Then, moving the alarm latch toggle switch at the CMU to the off position (unlatching the alarm) should silence the alarm, and re-set the unit to the “ready state”.

NOTE 1: This warm-up procedure only occurs when the unit is cold, or has not been recently operated. If the unit has just recently been turned off for example, and then turned back on again, the sensor may not need to be warmed up. If the sensor is already warmed up sufficiently, the unit will go right to the “ready state”.

NOTE 2: If the red light does not go out and the horns do not silence, usually within 30 seconds or so, the unit is not operating properly, and the sensor needs to be adjusted by the user . Re-adjust the sensor by placing a small screw driver into the small round adjustment port next to the RSU sensor housing to engage the small brass alarm adjustment screw within. Turn this screw slowly clockwise until the red light on the RSU just goes out. The alarm can now be unlatched at the CMU, and the unit should be in the “ready state”.

NOTE 3: If the red light at the RSU alarm still will not go out after turning the adjustment screw clockwise the maximum number of turns (10-12 complete turns), the unit is malfunctioning, and should be removed from service and repaired in accordance with company procedure. This could happen for example, if the sensor got wet, was exposed to a very high concentration of combustible gas, or non-standard testing procedures.

Performing a “Quick Check”

Once it is determined that the unit is warmed up properly, and is in the “ready state”, it is now ready for the “Quick Check” gas test as follows:

Setting-up the “Quick Check Kit”

• Screw the regulator/flow valve into the gas cylinder hand tight. Check the gauge to ensure that there is sufficient gas in the cylinder to perform the test (a brand-new full cylinder should indicate 200+ PSI).

Using the “Quick Check Kit” to test the Multi-RAM RDA IIIA

• Loosely connect the short plastic hose to the valve on the regulator. Now place the other end of the hose into the middle hole of the square sensor housing on the bottom of the RSU. Next,
• Fully tighten the short hose onto the regulator valve. The test gas should now flow through the hose into the sensor housing. The unit should go into the “alarm state” (red lights should light and alarms sound at both the RSU and CMU) (normally within 10 seconds or less).
• Once the unit goes into the “alarm state”, remove the hose and immediately disconnect it from the regulator to conserve the test gas. The red light on the RSU should then go out (normally within 10 seconds or less) and the alarm can then be unlatched by toggling the latch switch on the front of the CMU.
• If the system operates properly as described above, the unit is in the “ready state”.

Adjusting the alarm set point (if necessary)

• If it did not react as described, the following additional steps are required by the user before putting the unit into service to ensure that the alarm set point (10% LEL) is adjusted properly.
• With the regulator flow valve and hose connected to the test gas cylinder, and test gas flowing, place the end of the hose into the center sensor opening as described previously.
• Then, place the small screw driver provided with the “Quick Check Kit” into the small round adjustment port next to the sensor housing to engage the small brass alarm adjustment screw within.
• With the test gas still flowing, turn this screw slowly counter-clockwise until the RSU red light just comes on, and the unit goes into the “alarm state”.
• Then, remove the test gas hose and wait for the RSU red light to go out (normally within 10 seconds).
• The alarm can then be unlatched at the CMU.
• If the alarm still cannot be re-adjusted with this procedure, the unit must not be used until it is repaired by U-TECK in accordance with company practices

NOTE: The procedure described above is not a calibration, but rather an adjustment of the sensor by the user. A calibration can only be performed by a factory trained and authorized person, using special “Calibration Gas”.