K-Tec MT2000 manual Direct Reflect Mode standard cont’d, Ultra Low Dielectric ULD Measure Method

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2.3.1Direct Reflect Mode (standard) (cont’d)

The measurement principle using TDR is based on the fact that a dielectric constant discontinuity or geometric change will yield a negative pulse having certain amplitude below the baseline. The greater the dielectric constant difference, the greater the negative amplitude of the return signal. This means that a signal will show up on the baseline if there is a substantial change from a nozzle diameter to an open tank, for example, as signal plot at the process connection. This fact needs to be taken into account in order to configure the MT2000 properly (Consult section on commissioning).

Displayed in Figure 2.1 is the return signal, as one would see it on an oscilloscope. Refer to troubleshooting section for oscilloscope set up. Abbreviations used are:

GS

Gain Setting

BLK

Blanking

THV

Threshold Voltage

URV

Upper Range Value (20 mA)

LRV

Lower Range Value (4 mA)

LL1

Liquid Level 1

L1

Unmeasurable Zone (Top of Probe)

L2

Unmeasurable Zone (End of Probe)

Figure 2.1

2.3.2Ultra Low Dielectric (ULD) Measure Method

To effectively measure the level of very low dielectric products a different methodology is needed due to the poor reflection of the pulse on the surface of the product. This reflection is not strong enough to make a reliable level measurement. To achieve reliable and precise measurement the MT2000 uses the Ultra Low Dielectric (ULD) measurement method. This method requires the use of a flexible cable utilizing a weight / target assembly at the bot- tom end of a precisely known length. The pulse travels through the air at a known velocity and then passes through the product at a reduced velocity depending on the product dielectric constant.

Note: Reference Section 4.4.4 for ULD Mode setup and configuration.

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MT2000-0200-01 Rev f (10-2007) DCN0160

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Contents Guided Wave Radar Level Transmitter Table of Contents List of Figures AppendicesIntroduction Storage Information Ambient TemperatureOverview Measurement cycle consists of the followingDirect Reflect Mode standard cont’d Ultra Low Dielectric ULD Measure MethodInstallation Mounting RequirementsMT2000 Guided Wave Radar Guidelines Factory Default ConfigurationShortening of Probe URV = Probe Length LRV = 0 in. / 0 mmCommissioning WiringQuickstart Procedure MT2000 Guided Wave Radar Guidelines cont’dQuickstart Procedure cont’d Verify Proper Power-UpSetting the 4mA and 20 mA Points Using the Pushbutton Menu LCD Menu Operation Calibration MenuDetailed Configuration Parameters Direct Mode Blanking Menu Threshold Level Parameter THV and Gain Setting GSThreshold Level Parameter THV and Gain Setting GS cont’d Advanced Parameter SettingsL1O Advanced Parameter Settings cont’d KO & KGUltra Low Dielectric ULD Mode Configuration = H * Sqrt DC H + LDC = I + H L / H2 Setting the DAC trim Ultra Low Dielectric ULD Mode Configuration cont’dAdvanced Output Configuration DAC TrimFigure6 4mA & 20mA Calibration Using Actual Level Input Bench Calibration of the 4mA & 20mA PointsReversing The Output Action Using Actual Level Input Jumper Switch SettingsTroubleshooting Information Possible SymptomsValid Current Loop Outputs Honeywell DE Output Option Possible Symptoms cont’dElectronics Module Replacement Interoperability and Conformance ClassHart Communicator Hart Protocol Interface OptionOperating Modes CompatibilityGlossary of Terms LRVAppendices Appendix a Sensor TrimConfiguration 2 Hidden Menu END CFG MenuTMP Appendix C Linearization To access the linearization tableSetting up Linearization Table Points To clear the linearization tableAppendix D Interface Applications MT2000 InterfacePrerequisites Use and setup of the oscilloscope for the MT2000Scope Settings Channel a Channel BAppendix F CE Certificate of Conformity Appendix G Exida Certificate MT2000-0200-1 Rev f 10-2007 DCN0160 MT2000-0200-01 Rev f 10-2007 DCN0160 MT2000-0200-1 Rev f 10-2007 DCN0160 10a Appendix I Mounting Configurations3a, 3b 10bAppendix J Warranty Statement Year Warranty for
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