Bacharach GDC-350 Operation Manual

Contents

Bacharach GDC-350 Operation Manual Manual pdf 35 page image

GDC-350 Operation Manual5909-9000 Rev 1 29NOTE: When calibrating solid-state sensors for combustibles orrefrigerants, the span gas must be humidified. The use of ahumidification chamber is required. The humidification chamber sits inline between the cylinder of span gas and the calibration adapter.Remove the sponge inside the chamber and wet it under the tap.Squeeze out the excess water so it is not dripping wet and place it backinside the chamber. As gas flows through the chamber, it absorbs waterwhich acts to humidify it and the humidified span gas flows over thesensor. (See table on page 34 for ordering information.)5.4. Calibrating the On-Board SensorSETTING SPAN GAS VALUEStep Setting Span Gas Value Procedure1 Move the jumper on J6 to P2 and move the jumper on J7 to P2.2 The audible alarm beeps once for confirmation. The system is nowwaiting for the user to set the desired span value.3 Attach the volt meter leads to test points TP1 and TP2.4 Using the UP or DOWN push-buttons, achieve the calculated voltage onthe volt meter.5 Move the jumpers from J6 and J7 back to their P1 resting positions.CALIBRATING THE NULL (ZERO)Step Calibrating the Null (Zero) Procedure1 Attach a regulator to a cylinder of zero air (or nitrogen).2Insert the calibration adapter into the sensor opening on the front of theenclosure. Use a slight twisting motion as you gently push the calibrationadapter into the sensor opening. If the calibration adapter is hard toinsert, moisten the “O” ring seal slightly then try re-inserting it.3 Open the regulator valve fully allowing zero air to flow over the sensor.4Move the jumper on J6 to P2 and move the jumper on J7 to P3. Theaudible alarm beeps once for confirmation. The system is now startingthe zero calibration stabilization time (30 seconds).5 If desired, attach the volt meter leads to test points TP1 and TP2. Thereading should be 0.0 VDC.6The instrument will beep twice when the calibration begins. Leave thezero air flowing over the sensor until the GDC-350 beeps three timesindicating the procedure is finished (1 minute).7 Move the jumpers from J6 and J7 back to their P1 resting positions andremove the zero air (or nitrogen).