July 5, 2022

This notice serves as formal communication of Critical Environment Technologies (CET)’s decision to discontinue the LPT-A Analog Transmitter and the LPT-A-VLT Ammonia Vent Line Transmitter. This decision will impact the availability of replacement parts, factory service/repairs and warranty.


Reason for Termination: 

We are nearing the end of our LPT-A stock and are unable to replenish it due to the unavailability of key components, some of which are no longer being manufactured. The Analog CGAS Detector launched in 2020, is a suitable alternative for the majority of applications.


Replacement Product and Backwards Compatibility: 

The LPT-A came standard with a relay, internal buzzer and 4-20 mA or 0-10 volt output, plus accommodated 7 series sensors. The CGAS-A does not currently have an internal buzzer or 0-10 volt output and accommodates 4 series sensors. However, it offers enhanced features like:

  • Plug & Play Smart Sensor technology for quick and easy sensor replacement at end of life; smart sensors come from the factory pre-calibrated
  • Larger, brighter display
  • USB port for configuration changes and firmware upgrades
  • Optional relay (not available with sticky gases)

On September 1, 2022, CET will release the CGAS-A with an internal relay and buzzer, and 0-10 volt output and 7 series sensor capability which will all become standard features. With the addition of these features the CGAS-A will fulfill all applications of the LPT-A.

Meanwhile, for replacing LPT-A devices in the field:

  • A CGAS-A with relay and remote strobe/horn can be used to replace an LPT-A using 4-20 mA output in the field.
  • If the relay and buzzer are not required, a CGAS-A without a relay can replace an LPT-A using 4-20 mA output.
  • Replacing an LPT-A using 0-10 volt output is currently 8+ weeks lead time.
  • The CGAS-A offers the same 4 series* gas sensor options as the LPT-A and follows a similar model naming convention.


TABLE 1: CGAS-A to LPT-A Equivalency Table



CGAS-A-SR410A, CGAS-A-SR22, CGAS-A-SR134A, etc. LPT-A-SR410A, LPT-A-R22, LPT-A-SR134A, etc.
etc. etc.

*A 4 series ethylene sensor should not be used for continuous monitoring of high levels of ethylene common in fruit ripening applications. Until the CGAS-A is released with the 7 series capability, the only option for replacement is using the LPT-M with digital output.

The CGAS-A-VLT-NH3-S will replace the LPT-A model used for monitoring ammonia levels in the vent line of refrigeration systems. The current lead time is 8+ weeks.


Impact on Replacement Parts, Factory Service/Repairs and Warranty

As CET is unable to manufacture several critical elements (like the circuit board) replacement parts are not available, effective immediately.


  • The CGAS-A will need to be purchased to replace an LPT-A.
  • LPT-A’s under warranty* will be replaced with a CGAS-A, with the remaining warranty intact.


TABLE 2: End of Service Timeline 



End of Sale Notification Date July 5, 2022
Last Time to Buy no stock remains
Warranty* 2 years from date of purchase
End of Technical Service July 5, 2024
Last Day Replacement Parts are Available no replacement parts are available

 *Refer to our Terms and Conditions of Sale for more information


Please contact our Customer Success Team at if you have questions or need further assistance.

pdf version