background image

Figure 2

Figure 1

3.74”

INSERTION 

LENGTH

6.1”

SHOWN WITH
2" TRI CLAMP

ANDERSON INSTRUMENT CO., INC.

WWW.ANDINST.COM

    1-800-833-0081
MODELU                   

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INPUT 18-36 VDC

M12 
CONNECTION

TEFLON COATING

2” for probe length < 20”

4” for probe length ≥ 20”

0.24” for probe length 

<

 20”

0.39” for probe length ≥ 20”

0.59”

TEFLON COATING

INSERTION 

LENGTH

0.3”

2” for probe length < 20”

4” for probe length ≥ 20”

Rev. 2.1                                                                   Doc 1136                                                                    Page 2 of 2

Section 4 - Installation / Calibration Verification  

Operation

 

• 

Probe may not be cut! Trimming the probe length will  

 

 

disable the sensor and VOID warranty.

 

• 

The process connection must have electrical contact  

 

 

with the tank, therefore LN’s must be clamped on  

 

 

fitting for proper operation.

 

• 

Single probe LN's are suitable for installation in linear  

 

 

metallic tanks with probe parallel to tank wall. Non-parallel 

 

 

installation will increase reading error.

 

• 

Dual probe LN's are suitable for installation in    

 

 

nonmetallic and/or non-linear tanks.

 

• 

Sensor probe must not touch tank wall.

 

• 

For accuracy and proper operation, measured media  

 

 

should be homogeneous with respect to temperature  

 

 

and conductivity. Media must have a conductivity of at 

 

 

least 1 µS/cm.

 

• 

The LN is shipped calibrated to the bottom of the  

 

 

Teflon® coating. Normally at installation, additional  

 

 

adjustments are not required. 

 

• 

A turndown of up to 30% below top of probe is possible  

 

 

if 20mA output is desired at less than full rod height.  

 

 

Follow SPAN ADJUST for this feature.

Calibration

Zero Adjust
 

1.  Connect power supply as shown in Section 1.

 

2.  Connect Digital MultiMeter to output. With empty  

 

 

vessel (uncovered probe) signal output is 2.4mA. 

 

3.  Fill vessel until level contacts probe. Adjust OFFSET  

 

 

until signal output is 4.0mA (see Fig. 1).

Span Adjust
 

1.  Connect power supply as shown in Section 1.

2.  Connect Digital MultiMeter to output. 
3.  Fill vessel until maximum level desired. Adjust SPAN
      until signal output is 20.0mA (see Fig. 1).
Note: 
• 

Probe will not measure in Teflon® coated zone. Maximum 

  

level must be below the Teflon® zone.

• 

Max turn down is 30% of full probe length (including  

  

Teflon® coated area) from the top e.g. 30” rod length  

  

with 4” Teflon® coating may adjusted from 26” down to  

  

21”. 

• 

Span and Zero are normally non interactive however  

  

significant turndown adjustment may require an   

  

additional Re-Zero step.

Sensitivity

Typically adjustment is not required. If calibration is needed, perform 
the following with the least conductive media:   
 

1.  Connect power supply as shown in Section 1.

2.  Fill vessel until media level contacts probe.
3.  Observe red LED labeled SENSITIVITY (see Fig. 2 LN 

Sensitivity Table).

  

• 

If the LED remains off or only blinks on briefly, turn  

 

SENSITIVITY clockwise.

  

• 

If the LED remains on continuously, turn    

 

SENSITIVITY counterclockwise.

Note:

The objective is to achieve state 3 on the LN 
Sensitivity Table. The red LED should be lit with a brief 
off blink.

Single Probe

Dual Probe

Sensitivity

Offset

Span

Sensitivity

Power

OUTPUT

PROBE

ON

OFF

ON

OFF

ON

OFF

ON

OFF

2.4 
mA

4-20 
mA

4-20 
mA

DO NOT 
ADJUST

4-20 
mA

LED

SENSITIVITY
ADJUSTMENT

DO NOT 
ADJUST

EXPECTED
WITH NO
LIQUID

INCREASE
SENSITIVITY

TOO
SENSITIVE

OPTIMAL

State

1

2

3

4

LN Sensitivity Table

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