K-Tec MT2000 manual Threshold Level Parameter THV and Gain Setting GS cont’d, L1O

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4.4.2Threshold Level Parameter (THV) and Gain Setting (GS) (cont’d)

The following values should be used as starting points:

For Mounting Configuration 1,2,3a and 3b, (direct insertion in tank - no stilling well

GS

THV

applications, no coaxial probes) with the following dielectric constant:

 

 

 

 

 

≥ 10

2*

1.5*

 

 

 

≥ 3 and < 10

2

1.7

 

 

 

 

 

 

For Mounting Configuration 4,5,6,7,8,9,10a & 10b with the following dielectric

 

 

constant: (ground plane probe / installation applications - coaxial probes stilling

GS

THV

well, EC chambers)

 

 

≥ 10

4

1.0

 

 

 

< 10

4*

1.7*

 

 

 

*Factory Default

Assuming the 4 mA point is set toward the bottom end of the probe and that the 20 mA point is set toward the top, for a given GS setting:

•If THV is set too high the output will either read high or spike high.

•If THV is set too low the output will either read low down to 3.8 mA, spike low, or be in fault high (21mA) or fault low (3.6mA).

•Adjust THV as needed to obtain a steady output reflecting the actual level over the usable measuring range.

NOTE: If a stable output cannot be obtained, refer to trouble-shooting section or to Appendix F for viewing sensor signal using an oscilloscope.

4.4.3Advanced Parameter Settings

•L1O

Level One Offset is used to offset the level output of the transmitter to match the actual level in your tank or vessel. This offset allows the transmitter to be calibrated so that the 4mA is equal to a value higher than zero. There are several cases when Level Offset can be used:

1.To accommodate for a non-measurable length at the bottom of the probe.

2.To accommodate for the length of the probe being shorter than the ac- tual length of the tank or vessel due to agitator or other devices near the bottom.

3.To synchronize two redundant transmitters

4.To allow a zero-based measured variable which is used when an EC measurement needs to correlate locally to a sight glass. It also simpli- fies setting the range (from tap to tap)

L1O can be positive or negative and as much as 50% of the sensor trim span (HTP- LTP). Figure 4.4 shows a typical L1O offset.

Example: If the end of the probe, in Figure 4-4, were 4 inches off the bottom of the tank the L1O Level Offset would be 4. If the Measured Level were 21 inches then the local indicator would indicate 25 inches (21 +4) and the 4-20 mAdc signal would indicate a level of 25 inches. This will provide local indication and signal of the actual level of 25 inches.

Measured

L1O

Figure 4.4

MT2000-0200-1 Rev f (10-2007) DCN0160

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Contents Guided Wave Radar Level Transmitter Table of Contents Appendices List of FiguresIntroduction Overview Ambient TemperatureStorage Information Measurement cycle consists of the followingUltra Low Dielectric ULD Measure Method Direct Reflect Mode standard cont’dMounting Requirements InstallationShortening of Probe Factory Default ConfigurationMT2000 Guided Wave Radar Guidelines URV = Probe Length LRV = 0 in. / 0 mmQuickstart Procedure WiringCommissioning MT2000 Guided Wave Radar Guidelines cont’dVerify Proper Power-Up Quickstart Procedure cont’dSetting the 4mA and 20 mA Points Using the Pushbutton Menu Calibration Menu LCD Menu OperationThreshold Level Parameter THV and Gain Setting GS Detailed Configuration Parameters Direct Mode Blanking MenuAdvanced Parameter Settings Threshold Level Parameter THV and Gain Setting GS cont’dL1O KO & KG Advanced Parameter Settings cont’d= H * Sqrt DC H + L Ultra Low Dielectric ULD Mode ConfigurationDC = I + H L / H2 Advanced Output Configuration Ultra Low Dielectric ULD Mode Configuration cont’dSetting the DAC trim DAC TrimFigureBench Calibration of the 4mA & 20mA Points 6 4mA & 20mA Calibration Using Actual Level InputJumper Switch Settings Reversing The Output Action Using Actual Level InputPossible Symptoms Troubleshooting InformationValid Current Loop Outputs Electronics Module Replacement Possible Symptoms cont’dHoneywell DE Output Option Interoperability and Conformance ClassOperating Modes Hart Protocol Interface OptionHart Communicator CompatibilityLRV Glossary of TermsAppendix a Sensor Trim AppendicesEND CFG Menu Configuration 2 Hidden MenuTMP Setting up Linearization Table Points To access the linearization tableAppendix C Linearization To clear the linearization tableMT2000 Interface Appendix D Interface ApplicationsScope Settings Channel a Use and setup of the oscilloscope for the MT2000Prerequisites 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 3a, 3b Appendix I Mounting Configurations10a 10bYear Warranty for Appendix J Warranty Statement
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