Panel Meter

Directions: For analog panel meters on Linaire test panels use a 3 1/2 digit DVM with 1% accuracy or better to check the calibration of panel meters. Customer will need some type of resistive load capable of handling 500 watts of DC power. Customer will need a shunt resistor (.01 ohm 1% 25watts minimum) or a DVM capable of measuring 15 Amps of current (usually 4 1/2 digit DVM). If using a shunt resistor measure the voltage across the resistor and multiply that reading by 100. A current regulated power supply is preferred for this test but a voltage regulated supply will work. With voltage supply start at 0 volts and advance voltage until required current is reached.

Items: There are two brands of meters. The meters can be returned to Linaire for repair and recalibration or replacement for a fee.

Notes: Adjust the meter pointer zero position carefully because this can cause an error across the entire range of the meter. Meter should be tested for smooth operation over the entire range of motion watching for places where the pointer may stick, this is the most common problem to occur with these meters as they age.

DC MICROAMPERES ANALOG METERS

Directions: For analog panel meters on Linaire test panels use a 3 1/2 digit DVM with 1% accuracy or better to check the calibration of panel meters. Before testing these meters the meter resistance must be checked. Set the meter load switch on the Linaire panel to position 1 and check for 1000 ohms +/- 10 ohms across the meter. (make sure that your DVM output is no more than 100millivolts across a 1000 ohm resister first, anything more can damage the meter). If meter resistance is out of limits most meters can be adjusted through a hole in the back of meter case. Adjust the resistance as near to 1000 ohm as possible. If resistance cannot be set properly the meter must be returned for repair or replacement for a fee. A 0 - 500 uA current source into 1000 ohm load will be needed for testing these meters. A dry cell battery, range resistors and a potentiometer for fine current adjustment can be used as a satisfactory source. Apply + voltage to meter + terminal for 0 - 500uA meter and 100-0-100uA meter for right hand deflection. For left hand deflection reverse the supply leads. Start with current source set to 0 uA and increase to meters max range.

Item: The microampere meter if found out of calibration can be returned to Linaire for repair and recalibration or replacement for a fee.

Notes: : Adjust the meter pointer zero position carefully because this can cause an error across the entire range of the meter. Meter should be tested for smooth operation over the entire range of motion watching for places where the pointer may stick, this is the most common problem to occur with these meters as they age.