# EXtended high and low limit calculator

- What is Lower Range Value (LRV) of a transmitter?
- What is Upper Range Value (URV) of a transmitter?
- What is extended lower limit value of a transmitter?
- What is extended higher limit value of a transmitter?
- Formula for calculating EHL and ELL value
- Example calculation:
- ELL value calculation
- EHL value calculation
- Extended high and low limit calculator

**What is Lower Range Value (LRV) of a transmitter?**

Lower range value is the smallest measurement that a device can calibrated to measure. Another name for the LRV is Zero.

**What is Upper Range Value (URV) of a transmitter?**

Upper range value is the maximum measurement that a device can be calibrated to measure. Another name for the URV is Span.

**What is extended lower limit value of a transmitter?**

In the event that the process variable falls below the instrument calibration range, the extended low range is employed to measure the process variable’s lower value.

**What is extended higher limit value of a transmitter?**

In the event that the process variable rises above the instrument calibration range, the extended high range is employed to measure the higher value of the process variable.

**Formula for calculating EHL and ELL value**

**ELL value = LRV-((URV-LRV)*ELL LIMIT %)**

**EHL value = ((URV-LRV)* EHL LIMIT %)+URV**

**Example calculation:**

For instance, the level of a tank with a range of -200 to 800 inch is the process variable to be monitored with Extended Low Limit (ELL) is set to 5% Extended High Limit (EHL) is set at 3%.

**ELL value calculation**

The Range is then 100 and the LRV is -200 inch

URV is 800 inch

ELL value = LRV-((URV-LRV)*URV LIMIT%)

ELL value =-200-((800-(-200))*(5/100))

ELL value =-200-(1000*0.05)

**ELL value = – 250 inch**

**The Extended Low limit value can be -250 inch if the Extended Low Limit (ELL) is set to 5%.**

**EHL value calculation**

EHL value = ((URV-LRV)* EHL LIMIT%)+URV

EHL value = ((800-(-200))*(3/100))+800

EHL value = (1000*0.03)+800

**EHL value = 830 inch**

The Extended high limit value can reach 830 inch if the Extended High Limit (EHL) is set at 3%.

**Extended high and low limit calculator**

The below calculator used to calculate the Extended high and low limit of the process variable

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