This Civil Defense radiation detector meter is taken through the following preventative maintenance, tests, and evaluations prior to calibration:
Successful completion of the above procedures has the meter then qualified to attempt calibration to mid-range of all it's scales.
- Confirm integrity of case, meter, and snap connections
- Check that extension cable is intact and serviceable on CD V-717's
- Clean battery contacts and battery terminals, as required
- Confirm good ground connections on circuit board
- Check screws attaching the circuit board to the case top
- Visual check of circuit board for metal foil cracks, cold solder joints, or solder bridges
- Clean circuit board with brush and solution, heat to dry
- Clean high megaohm resistors, as needed
- Clean high megaohm resistors switch, as needed
- Check for dirt contamination of the high impedence feed-thru insulator on ionization chamber, clean if necessary
- Test ionization chamber for loose (broken) internal components
- Test ionization chamber for leakage via Megohm meter, re-coat with clear varnish, if necessary
- Insert battery
- Perform Zero and Circuit Check operations after two minute warmup at Zero setting
- Check meter needle for free movement throughout range
- Commence a power-on 16-hour burn-in to recondition the electrometer tube
- Repeat the Zero and Circuit Check Test
- Perform stability evaluation of the meter needle throughout all the ranges. The needle should not deflect more than three of the smallest increments upscale (0.3 on the meter face) on the "X100", "X10", and "X1" scales and six increments (0.6 on the meter face) on the "X0.1" scale
- Remove batteries
- Check instrument case top gasket, apply light coat of D-5 compound to it, if needed
- Place fresh desiccant packet in case before closing
- Clean outside casing and tag it
Successfully passing the KI4U lab calibration, they are then certified fully ready for reliable, accurate and confident service in the field.
All calibration certifications of these Civil Defense survey meters is accomplished here with the CD V-794 calibrators built specifically for these type meters. This calibrator utilizes a N.I.S.T. traceable Cs-137 source that tests and calibrates (adjusts) mid-scale for all the ranges strictly in accordance with industry standards. KI4U, Inc. is licensed and authorized by the State of Texas to perform these calibrations at our lab here conforming to the standards as set forth by the State of Texas, FEMA, ASTM and the NRC.
Successfully calibrated instruments are returned with the label below affixed to them certifying their calibration and stating who calibrated it and when, along with the serial number and model designation.
Additionally, a Certificate of Calibration with the actual before and after accuracy responses for each of the different ranges available on the instrument is included.