Saint Hill Manor, East Grinstead, Sussex HCO BULLETIN OF 11 MAY 1969 | Saint Hill Manor, East Grinstead, Sussex HCO BULLETIN OF 11 MAY 1969 |
(Replaces HCO B of 27 July 1966, same name) | (Replaces HCO B of 27 July 1966, same name) |
METER TRIM CHECK | METER TRIM CHECK |
E-Meters can go out of trim during a session because of temperature changes. | E-Meters can go out of trim during a session because of temperature changes. |
Thus even if the meter is properly calibrated and reads at 2.0 with a 5,000 ohm resistor across the leads and 3.0 with 12,500 ohms, by the end of the session a pc can be apparently reading below 2.0 because the meter is off trim. | Thus even if the meter is properly calibrated and reads at 2.0 with a 5,000 ohm resistor across the leads and 3.0 with 12,500 ohms, by the end of the session a pc can be apparently reading below 2.0 because the meter is off trim. |
The following meter procedure is therefore to be followed AT THE END OF EACH SESSION (AFTER GIVING “THAT’S IT”): | The following meter procedure is therefore to be followed AT THE END OF EACH SESSION (AFTER GIVING “THAT’S IT”): |
1. DON’T MOVE THE TRIM KNOB | 1. DON’T MOVE THE TRIM KNOB |
2. PULL OUT THE JACK PLUG | 2. PULL OUT THE JACK PLUG |
3. MOVE THE TA UNTIL THE NEEDLE IS ON “SET” AT THE SENSITIVITY YOU WERE USING IN THE SESSION | 3. MOVE THE TA UNTIL THE NEEDLE IS ON “SET” AT THE SENSITIVITY YOU WERE USING IN THE SESSION |
4. RECORD THE TA POSITION AT THE BOTTOM OF THE AUDITOR’S REPORT FORM AS: “TRIM CHECK – TA = ...” | 4. RECORD THE TA POSITION AT THE BOTTOM OF THE AUDITOR’S REPORT FORM AS: “TRIM CHECK – TA = ...” |
5. IF YOUR METER IS KNOWN TO BE OUT OF CALIBRATION (as in Para 2 above) RECORD ALSO: “Calibration error – on meter = 2.0 actual” at the bottom of the form. | 5. IF YOUR METER IS KNOWN TO BE OUT OF CALIBRATION (as in Para 2 above) RECORD ALSO: “Calibration error – on meter = 2.0 actual” at the bottom of the form. |