Hello, I have just acquired a Smar LD400 to measure level in a closed tank. How do I configure the upper and lower range values?

Pressure Q&A

Expert’s Answer: New level range Smar LD400

Basically, there are 3 ways to do it. Two of them are through local configuration, without the need of a handheld. The third is through a field communicator. I personally find the handheld option easier, but this is a matter of choice. Some people still prefer configuring the devices locally without the need of carrying the handheld. Well, preferences aside let’s get down to business.

First, I will show you how to do it locally. There are two different types of local adjustments for the Smar LD400. In brief, the simple and complete adjustment modes. To change from one to another you will have to change some jumpers on the main board, the electronic part of your device.

Regarding the simple adjustment configuration, it is only possible to set the upper and lower range values with a reference. This means that you will have to apply pressure to the device and save that value as a reference value, rather than just typing it in.

In the complete adjustment configuration, you can only set up the URV and LRV without a reference.  In fact, you just need to choose a number for your reference and that’s it. Using the handheld you can do both with or without reference, but we will come to that later.

To set your device to simple or complete adjustment configuration you can follow the picture below.

Adjustment Configuration LD400
Courtesy of SMAR

Simple local adjustment

If you chose to configure the Smar LD400 on simple local adjustment it is pretty straight forward. On the top of your device there will be the Zero/Span adjustment holes. The Zero slot corresponds to the Low Value and the Span slot to the Upper Value.

To configure your Low Value simply apply the corresponding pressure. Then wait for it to stabilize. Lastly, insert the magnetic tool in the Zero slot. After 2 seconds your device should be reading 4mA.

To configure the Upper Value, you repeat the same process but this time with the UV pressure and inserting the magnetic tool in the Span adjustment hole. After 2 seconds the device should read 20mA.

Complete local adjustment

In the complete local adjustment you don’t need to apply the reference pressure, you can just set the value manually. To do so, set the jumpers on your main board to complete local adjustment and insert the magnetic tool to the Zero. This will get you into the main Menu of the device. To navigate through this menu simply keep pressing Zero and when you wanna access an option inside a menu hit Span. To set the URV and LRV in the main menu select the Range menu. Inside Range there are the LRV and URV options, in which you can either increase, decrease or save the values. Remember Span selects the action and Zero moves through the menu.


Using the handheld with its User Interface (UI) is simpler. As as result, the navigation is easier and more intuitive. When you select your device LD400 on your handheld you will have a Range menu. Inside this menu you have the options to set the URV and LRV with or without reference. With reference you will have to apply the pressure just like on the local configuration. When you are working without a reference you just need to type in the value and that’s it.