| General |
| The Model 542 is a versatile, programmable gas analyser, based on the principles of thermal conductivity, capable of measuring almost any combination of gases. The instrument is especially suitable for measurements of mixtures containing hydrogen or helium. With the use of sensitive control systems, the thermal conductivity analyser can detect gases down to parts per million levels and up to full concentration. The analyser is pre-programmed for a wide range of sample and reference gases, easily selectable from the simple front panel menu. Calibration settings, for each combination of gases used, are stored in an internal memory and are recalled automatically every time a particular gas mix is required. This enables quick and easy switching between gas combinations. Sophisticated microprocessor electronics enable the fastest possible response time, excellent stability and flexibility. Sample pressure and flow are internally controlled allowing connection to a wide range of pressurised samples. Options include automatic calibration, when the instrument can be set to perform a zero and span calibration at timed intervals. Features Programmable for different gases Built-in linearisation Fast response Good stability Insensitive to sample flow Computer communications Autoranging electronics Applications Gas mixing Welding gases Heat treatment atmospheres Hydrogen/helium purity Food packaging gases |
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| Technical Specification |
| Ranges | Dependent on selected gas mix Adjustable, auto-ranging Typical: 0-1000ppm (H2 in N2) 98-100% (O2 in Ar) |
| Resolution | 0.5% or better |
| Accuracy | ±2% of range |
| Response time | 90% of reading in 20 seconds |
| Calibration range | 0-100% of selected measure gas Automatic timed calibration as standard Auto zero |
| Measuring cell type | Thermal conductivity/katherometer, ultra stable |
| Operating Conditions |
| Sample inlet pressure | 1.0 to 7.0 Barg |
| Sample flow rate | Internally controlled (max 250ml/min) |
| Sample temperature | -10 to 40°C |
| Ambient temperature | -5 to 50°C |
| Sample connections | 1/8" OD compression fittings (others on request) |
| Unsuitable gases | Corrosive gases (contact Systech for alternatives) |
| Power Requirements |
| Power supply | 230/115V ±10%, 50/60Hz at 40VA |
| Display type | 4 digit high visibility LED and 12 digit alphanumeric |
| Cabinetry And Mounting |
| Enclosure | Sheet steel |
| Installation | Bench or panel mounting |
| Dimensions | 535W ~ 165H ~ 300D (mm) |
| Panel cutout | 445W ~ 132.5D (mm), if required |
| Weight | 12kg |
| Ingress protection | IP40 |
| Options |
| Alarms | Two adjustable alarms with volt-free, change-over contacts Fully configurable over complete range. Contact rating 10A@ 240V ac/30V dc |
| Analogue output | 0-10V, 4-20mA (0-20mA) isolated Max loop resistance 500 Ohms |
| Serial interface | Allows connection to a computer |
| Multipoint sampling | Sequenced sampling for up to 8 sample lines |
| Sample gas pump | Externally mounted |
| IP55 enclosure |
| Sealed reference gas | Dependent on application and range (contact Systech for options) |
| Corrosive gases | Contact Systech for information on alternative options |
Gas Analyzers 
