All of Overhoff’s Water monitors have been recently reworked to take advantage of the latest technologies and to use, the new, smarter ORO data analysis software.
The remarkably Low Cost and great sensitivity level of Model TMW-3 is achieved by,
1. Using the Sample and Count Methodology
2. Removing some non-essential and special purpose features. And then letting the user decide which specialized features to add back as user selected Options.
3. Making use of the latest technologies.
SAMPLING VS. CONTINUOUS REAL-TIME
“A Sample and Hold System” such as model TMW-3 will periodically extract a water sample, condition it, inject it into the measurement cell, count it for a long time, eject the sample and repeat. The longer the measurement time the lower the MDA, minimum detectable level.
PRO: Gives very sensitive, accurate measurement in a simple low cost machine.
CON: Short-term changes or releases that occur between one sampling moment and the next will be missed.
APPLICATION: Useful where long-term Tritium variations and trends are important, but short-term variations are not. Example: use this system to accurately document long-term increase (or decrease) of tritium levels.
“A Real-time Continuous System” such as model HWLD-1925 will continuously extract water sample (or at very short intervals), condition it, inject it into the measurement cell, count it, eject the sample and repeat.
PRO: Gives very sensitive, accurate measurement. Even short-term changes or releases will be measured and recorded because the samples are taken one right after the other, so no “events” will be missed. Can act almost as a real-time alarm in case of a leak, spill or attack.
CON: Higher cost.
APPLICATION: Useful where immediate notice or alarm is needed or when fine-grained time variations are of interest in order to track down the cause of an event.
NOTE: In situations where there is a persistent change or trend in the Tritium concentration level, a real-time continuous monitor with smart software, can also benefit from averaging the counts over very long times to achieve remarkable low MDA, minimum detectable level.