We understand that sometimes our customers have questions that they would like to have answered.
Below you will find answers pertaining to the GasCard NG and Guardian +.
The easiest way to identify if the sensor is operating is to check to see if the IR source is flashing and if the blue power LED is on.
Has power been correctly fitted to the positive (+24) & negative (-0) terminals on J5. Ensure they are not connected to the output terminals (O/P+ & O/P-) on J5. Also check the power supply. (Can it supply sufficient power, See section 6.1 in the operating manual).
Unlike the Gascard II the Gascard NG has built in pressure and temperature sensors and using these it will automatically correct the output for atmospheric changes.
The Gascard NG has self monitoring routines that check for faults within the system and reports these using LED’s on the main PCB and on the display if one is fitted. The main functions of the 6 LED’s on the Gascard NG main PCB are described in the table below.
| LED No | Colour | Function | Description | Normal Condition |
|---|---|---|---|---|
| 1 | Orange | Lamp Fault (If ON or Flashing) | LAMP FAULT | OFF |
| 2 | Red | Detector Fault (If ON or Flashing) | DET. FAULT | OFF |
| 3 | Green | Transmitting Data (If Flashing) | TX | Flashing |
| 4 | White | Receiving Data (If Flashing) | RX | OFF |
| 5 | Yellow | Calibration Running (If ON) | CAL | Flashing |
| 6 | Blue | Power Indicator (Powered if ON) | PWR | ON |
The table below lists the detectable errors and describes the way in which they are indicated to the user by the LED’s. On the 4 digit LCD if one is fitted the errors are reported as “F. XXX” where XXX is the fault number.
| Error # | Description | LED Indication | Possible Cause and Remedial Action |
|---|---|---|---|
| 1 | Lamp fault | LED1 (Orange) & LED2 (Red) both on | Check the infrared source voltage. Change the infrared source (lamp). |
| 2 | Concentration < -5% Range | No LED indication | Check the detector. |
| 3 | Concentration > 130% Range | No LED indication | Check the detector and gas. |
| 4 | DSP temperature > 70C | LED2 (Red) flashing slowly (about 2s period) | Make sure the ambient temperature is within specification. Use gas cooling if necessary. |
| 5 | DSP temperature < 0C | LED2 (Red) flashing slowly (about 2s period) | Make sure the ambient temperature is within specification limits. |
| 6 | Head temperature > 70C | LED2 (Red) flashing fast (about 1s period) | Make sure the ambient temperature and the gas temperature are within specification. Use gas cooling if necessary. |
| 7 | Head temperature < 0C | LED2 (Red) flashing fast (about 1s period) | Make sure the ambient temperature and the gas temperature are within specifications. Temperature sensor fault. |
| 8 | Reference signal Low (< 50%) | LED1 (Orange) & LED2 (Red) flashing alternately | Damaged or contaminated optics. Check signals and gains. |
| 9 | Sample Signal Low (<10%) | LED1 (Orange) & LED2 (Red) flashing alternately | Damaged or contaminated optics. Check signals and gains. |
| 10 | Sample channel too close to zero value during Span Calibration | LED2 (Red) flashing fast (about 1s period) | Span calibration routine has failed. Recalibrate zero and span (zero gas first). |
| 11 | Calibration coefficients fault | LED1 (Orange) on continuously | Check stored coefficient values. |
| 12 | Flow fault (Guardian NG) | No LED indication | Check the pump and pipe work for blockages or faults. |
The easiest way to identify if the sensor is operating is to check the LCD display for readings.
Try checking/replacing the fuse (F1) and confirming what voltage it was set to run on (See sections 3.9 & 4.4 in the operating manual).
It’s possible that the fuse (F1) has blown as a result of applying 240V to the sensor when it was set to operate at 110V.
Check/replace fuse (F2) (See section 4.4 in the operating manual).
The sensor is indicating that it is in the “Fault” condition “Low Flow”. This fault indication is normally caused by either the blocking of the inlet filters or tubing (restricting the flow of gas through the sensor) or the failure of the pump diaphragm (causing gas to be blown into the sensor rather than around the gas path).
Try checking/replacing the first inlet filter then the second (See section 4.1 in the operating manual) and then the condition of the pump (See section 4.5 of the operating manual).
If checking these does not correct the fault indication then a service should be arranged at Edinburgh Instruments.
The sensor is indicating that it is in the “Fault” condition “Err”. This indication of a fault can be caused by many factors (Failed IR source, signal failure, contaminated optics, electrical fault etc). When a fault indication of this type occurs the sensor will have to be returned to Edinburgh Instruments for a full service.
