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Related Manuals for Alpha Moisture Systems AMT
Summary of Contents for Alpha Moisture Systems AMT
- Page 1 Alpha Moisture Systems AMT Dewpoint Transmitter 1527 Instruction Manual ...
- Page 2 Monday ‐ Thursday 8.30am ‐ 5.30pm Friday 8.30am ‐ 5.00pm Saturday and Sunday ‐ Closed Authorised Distributor Contact Information: Issue 10 07/12/2023 1527 AMT User Manual ...
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Page 3: Warranty
Warranty Alpha Moisture Systems Ltd. (AMS) warrants the products it manufactures, or distributes, to be free of defects in material and workmanship under normal use and service when operated within the specified design limitations for a period of 12 months from date of initial shipment. Under this Warranty, AMS will, at its discretion, repair or replace any component that upon examination by AMS or its duly authorized representatives proves to be defective during the warranty period, provided the system is returned to the factory for inspection and repair shipping prepaid. Improper or unauthorized maintenance, storage, repair, or alteration of any kind by personnel other than AMS, or its duly authorized representatives, may void all warranties. Warranty may also be voided for misuse, neglect, accident, corrosion, and improper installation. This Warranty is exclusive and in lieu of any and all other warranties of merchantability, fitness for a particular purpose, or any other warranty, expressed or implied, and all other liabilities and obligations on the part of AMS. AMS will not be liable for any other claims or damages, either direct, indirect, or consequential arising out of the use of its products. Original manuals are prepared in English. Translations in other languages may be available, but in the event of any discrepancy, the English version will be considered as the official version, which is subject to change without notice. NOTE: Corrosive Gases: The Sensor should not be exposed to corrosive gases (or corrosive contaminants in the gas sample) as these can chemically attack the sensor, impairing calibration accuracy and/or damaging it beyond economic repair. Examples of such gases are mercury (Hg), ammonia (NH ), chlorine (Cl ) etc. Strong oxidising agents such as ozone (O ) should also be prevented from coming into contact with the sensor. For more information please contact us below. ... -
Page 4: Table Of Contents
Index 1 Overview ...................... 1 1.1 Gas Compatibilities .................... 1 2 Installing the AMT in an Air/Gas Sampling System .......... 2 2.1 Piping installation ...................... 2 2.2 Component Index ...................... 3 2.3 Installing and Commissioning the Model AMT Transmitter ........ 3 2.4 Wiring the AMT ...................... 4 2.5 ... -
Page 5: Overview
AMT Dewpoint Transmitter 1 Overview The Model AMT Dewpoint Hygrometer is a 2 wire 4‐20mA loop powered transmitter, used for continuous measurement of moisture in a process gas or compressed air. The Model AMT transmitter can be factory configured to output a 4‐20mA linear signal for any of the following moisture units: ‐ °C or °F dewpoint, ppm(v), ppb(v), g/m3, and lb/MMSCF. The ultra high capacitance sensing element is long lasting and offers excellent sensitivity, repeatability and response speed. Each unit is calibrated, traceable to International Humidity Standards, and is supplied with a Certificate of Calibration guaranteeing accuracy to ± 2°C dew point. The transmitter also incorporates an Automatic Calibration (AUTOCAL) feature, which allows the user to carry out field calibration / span check. The AUTOCAL feature is operated by means of two small buttons built into the transmitter body. To avoid accidental corruption, the buttons are locked in normal operation and can only be activated by following a specific routine. The RISC microprocessor circuitry of the Model AMT transmitter allows high resolution with advanced self‐diagnostics for fault conditions. It also enables periodic re‐calibration of the moisture sensor, storing calibration data within the fully self‐contained unit. Loop powered, by a 12v to 28v dc source. The Model AMT transmitter will provide the user with a linear 4‐20mA signal over the chosen range. The mechanics of the Model AMT transmitter have been designed to cope with extreme environmental conditions. The rugged stainless‐steel construction offers protection to IP66 (NEMA4X), with the transmitter electrical connections made via secure industrial type connector (size C, DIN EN 175301). The AMT transmitter can withstand 35,000 kPa (350bar) maximum pressure and by employing low resistance cable, the transmitter can be located at significant distances, in excess of 1000 meters, from the data collection point. Designed with the operator in mind, for reliable and accurate measurements, the Model AMT is extremely easy to install and operate, requiring little or no maintenance. 1.1 Gas Compatibilities ... -
Page 6: Installing The Amt In An Air/Gas Sampling System
AMT Dewpoint Transmitter 2 Installing the AMT in an Air/Gas Sampling System The piping installation schematic diagram (see section 2.1) shows all components, which could be used in a dry gas measurement application although not all the items shown will be required for every installation. The flow rate, although not critical to the sensor measurement, should be low enough to avoid abrasion to the sensor surface without being so low as to extend the system response time to an unacceptable level. In general, a flow rate of between 2 and 3 litres/min at NTP will give the right balance. The sensor is a variable capacitor, which is directly affected by changes in partial pressure of water vapour. These changes are proportional to the dew/frost point temperature. Partial pressure of water vapour is directly affected by total pressure and, this being the case, the instrument will display the dew/frost point temperature at whatever total pressure the sensor is exposed, therefore care should be taken to ensure that the sample pressure, at the sensor is that at which the dew/frost point readings are required. The measuring transmitter can be installed directly into the process line but this does create problems with access for maintenance and calibration. It is for these reasons that we recommend that the transmitter be installed in a bypass, fast loop or total loss sample system where the transmitter is accessible without interrupting the main process flow line. 2.1 Piping installation ... -
Page 7: Component Index
5) Sample Pressure Gauge – This is not a critical part of the moisture measurement but may be required if Dew/Frost point measurements are to be made at higher than atmospheric pressure. 6) Measuring Transmitter, see “Appendix A – AMT with Connector, General Arrangement”. 7) Transmitter Holder, see “Appendix B – Transmitter Holder General Arrangement”. -
Page 8: Wiring The Amt
AMT Dewpoint Transmitter Close the inlet isolation valve and install the transmitter into the transmitter holder. Locate and secure the four‐pin transmitter cable connector in positioned on the transmitter. Use the locking screw in order to affect a weatherproof seal. Open the inlet valve slowly, again and, by opening all valves after the transmitter holder, allow a low‐pressure purge through the whole sample system. (Note. If a closed by‐pass loop is installed, this section of the procedure is not possible). Set the required pressures and flows within the sample loop. This completes the installation and commissioning but, on initial start‐up, it could take several hours for the system to reach equilibrium. 2.4 Wiring the AMT The AMT is a 2‐Wire 4‐20mA transmitter. 1. Typical 4‐20mA electrical connection 4‐20mA Indicator Pin 1 Pin 2 Power 4‐20mA Supply +ve +Ve Return 4‐20mA ... -
Page 9: Connector Pins
AMT Dewpoint Transmitter 2.5 Connector Pins Red = 12 to 28V dc Power Supply Pin 1 Pin 2 Blue = 4‐20mA Current Return Powr Supply 4‐20mA +ve Return 3 Normal Operation 3.1 Analogue 4‐20mA Mode (2‐wire) In normal operation, the transmitter will produce a 4‐20mA signal, which is proportional to the level of moisture in the gas being monitored. The moisture reading is sampled and up dated once per second. The AMT has 3020 distinct steps over the 4 to 20mA range corresponding to a resolution of 0.005mA. 4 Autocal Warning Do Not power down during the AutoCal process as this can lead to corruption of the AMTs memory. ... -
Page 10: Pre-Conditioning The Transmitter
AMT Dewpoint Transmitter 4.1 Pre‐conditioning the transmitter To perform the autocal, the transmitter needs to be removed from the process gas at which point the display/indicator will read the ambient dewpoint or full scale (if the ambient dewpoint level is above the range of the AMT). Expose the transmitter to the known autocal moisture level and allow the transmitter to attain equilibrium. (For technical questions and advice on the time taken to attain equilibrium Contact your AMT supplier) Method 1: ‐ Expose to a known moisture level. (Applicable to all versions of AMT Transmitters) If a known gas is available within the range of the transmitter, then the AMT can be AutoCaled against this value. Method 2: ‐ Saturating method. (Only applicable to 0°C (32°F) and –20°C (‐4°F) top end range AMT transmitters) When the AMT sensing element is exposed to a dewpoint level above the top end range of the transmitter, the sensor will saturate and the transmitter can be AutoCaled to 0°C or – 20°C. For both 0°C and –20°C AMTs, ambient dewpoint is usually adequate to saturate the sensor. Method 3: ‐ Set against Ambient moisture level. (Only applicable to 20°C (68°F) top end range AMT transmitters) When the ambient dewpoint is known, then the AMT can be AutoCaled to the ambient value. 4.2 Entering Autocal Mode Once the transmitter has been pre‐conditioned, the AutoCal Mode of the AMT can be activated. Press and hold the ‘W’ and ‘D’ buttons, simultaneously for 5 seconds. ONLY PRESS THE BUTTONS IF THE SENSOR IS PROPERLY PRE‐CONDITIONED. FAILURE TO COMPLY WILL CORRUPT THE TRANSMITTERS CALIBRATION. The attached 4‐20mA display will (after the 5 seconds) indicate the bottom range of the AMT (or 4mA if reading current) for 5 seconds, confirming that autocal mode has been entered. The buttons should be released once the display indicates the bottom range. ... -
Page 11: Adjust The Autocal
Method 1: ‐ Adjust the AMT reading until the indicator reads the known moisture level. Method 2: ‐ Adjust the AMT reading until the indicator reads 0°C or –20°C whichever is applicable to the AMT being AutoCaled Method 3: ‐ Adjust the AMT reading until the indicator reads the known ambient moisture reading. 4.4 Completing the autocal Once the desired value is reached, the autocal process can be completed simply by leaving the buttons untouched for 30 seconds. After the 30 seconds, the display will indicate the bottom of the range for a period of 5 seconds and then the AMT will exit the autocal mode. The AMT will now output the corrected dewpoint and can be reinserted into the process. A graphical description of the autocal modes is given on the next page. 4.5 AMT Range AutoCal Method Lookup Table Use the table below to decide which AutoCal methods are appropriate for your AMT. Range Methods Appropriate ‐80 to –20°C ‐112°F to –4°F 1 & 2 ‐110 to –20°C ‐166°F to –4°F 1 & 2 ‐120 to –20°C ‐184°F to –4°F 1 & 2 ‐65 to 0°C ‐85°F to 32°F 1 & 2 ... - Page 12 AMT Dewpoint Transmitter 8 ...
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Page 13: Faults/Errors
AMT Dewpoint Transmitter 5 Faults/Errors If the sensor is short‐circuited, the transmitter will produce a constant 20.75mA output. If the sensor is open‐circuited, the transmitter will produce a constant 20.50mA output. 6 AMT Specification Display : Compatible with the 4‐20mA DS1200 Dewpoint Meter. Output Signal : 4 to 20mA Linear Operating Voltage : 12V ‐ 28V DC. Reverse polarity protected. Sensing element : Ultra High Capacitance ‐ Aluminium Oxide Type Autocal : Field calibration / Span check facility. Factory calibration : Supplied with Certificate of Calibration traceable to NPL Accuracy ... -
Page 14: Appendix A - Amt With Connector, General Arrangement
AMT Dewpoint Transmitter 7 Appendix A – AMT with Connector, General Arrangement 8 Appendix B – Transmitter Holder General Arrangement 10 ...
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