Continuous Output and Fluid Consumption Rates Explained
When comparing fluid consumption and continuous operating rates, it can often seem as if the numbers do not add up.
For example, in numbers taken from the ZR45 User Manual/Specification sheet:
Continuous effect output
Fluid consumption (max.) : 210 ml per minute
Maximum operating time, maximum output, 5L of fluid: 1.18 hours
At 210ml per minute, it would seem that 5l of fluid would be used in approximately 24 minutes, not the stated 1.18 hours.
To understand why this is not the case, we need to understand the mechanics of continuous output.
The summarised answer:
The maximum consumption is the rate measured for the initial 100% output trigger. For the first 10-20 seconds of true 100% output the device will consume more fluid than over the next 20 seconds (as the pump will start to reduce output) and then the pump will reduce further. So if performing short bursts (for example 100% for 3 seconds, 0% for 3 seconds) the device will use a lot more fluid in 1 minute than performing a constant trigger for 1 minute.
The maximum operating time for 5l is how long it will take to empty the included 5l bottle if you trigger the machine at 100% constant output, not in bursts.
Detailed explanation:
All of the ZR range (and any other smoke machine in our range) will operate continuously, but not at true 100% output constantly – this is due to “pump ramping” technology, built into all smoke machines designed since 1998.
This is a software/hardware control system that allows one to change the speed of the fluid pump(s) depending on the actual current operating temperature of the heater.
As fluid flows through the heater to create the smoke it rapidly cools the heater. The heater thermocouple (temperature sensor) reports the live temperature of the heater back to the main PCB and when it drops below a specified lower threshold, the PCB will supply power to the heater to try to maintain/recover as much temperature as possible.
It will try to keep the heater within the correct operating temperature range so that the fluid will 'burn' correctly and produce 'safe' smoke output.
Historical methods of continuous output
On older machines (such as the Martin Magnum 2000 unit) pump control was not available. If the temperature dropped beyond the lower threshold (usually about 10 seconds of output) then the software/hardware would need to physically stop the output to prevent 'wet' smoke output (where the temperature is not enough to correctly convert the fluid to smoke).
Once the heater had recovered enough temperature to be within the safe temperature range again, the software/hardware would then allow the pump to operate again and resume smoke output.
This would result in an on/off output - not continuous.
The addition of pump ramping
From 1998 onwards (JEM ZR22 model onwards) the addition of pump ramping allowed better software/hardware control of the heaters and pumps, and altered output of the fluid pump in relation to the heater temperature so that the temperature drop is less rapid at its lower temperature range.
The power being applied to the heater and the reduced smoke output allow the heater to get to a stage of equalized temperature gain/loss.
This means that the output does not have to be stopped as the heater will now stay within its safe operating temperature range (but at a lower output level) creating 'safe' smoke.
If triggering the machine at 100% output, there will be approx. 10-15 seconds of true 100% output. During this time the temperature in the heater will drop rapidly. Once below a pre-defined temperature threshold the pump speed will then slow until an equal state of heat gain/loss is reached.
Despite triggering at 100%, the real smoke output may be as low as 40% but still outputting, and it will not stop. After 30 seconds or so, you may see the output rise slightly (to 50% for example) as the temperature gain is greater than the temperature loss.
It will maintain smoke output at this lower output level as long as sufficient fluid is available.
If output is paused long enough to regain optimal temperature (approx. 30s) the next time the machine is triggered at 100% output it will provide full output and the cycle will repeat.
If you just do short bursts of 100% output then the heater will recover enough temperature between triggers to allow each burst to still be true 100% output. If you trigger the machine at a lower output level (for example 40%) then the “pump ramping” will not have as much effect on the output as the drop in temperature will not be as extreme. So you will get a much smoother constant output level, for example staying around 40% output as long as you can keep it sufficiently supplied with fluid.
So this is true constant output - but the level of output is varied depending on the demand of the heater. The unit does not have to stop to reheat, but the output level will drop to allow heat recovery/stabilisation.
Fluid Consumption
The maximum consumption is the rate measured for the initial 100% output trigger. For the first 10-20 seconds of true 100% output you will consume more fluid than over the next 20 seconds (as the pump will start to reduce output) and then the pump will reduce further. So if you were doing short bursts (for example 100% for 3 seconds...0% for 3 seconds) you will use a lot more fluid in 1 minute then you would if you did a constant trigger for 1 minute.
The maximum operating time for 5l is how long it will take to empty the included 5l bottle if you trigger the machine at 100% constant output, not in bursts.
You will initially use a large amount (for 10-20 seconds) but as the output drops and stabilises at a lower output level (due to pump ramping) the consumption will go down and you will get a longer run time.
No smoke machine of any brand can claim to operate at true 100% output constantly (unless 100% output is actually a very low output value compared to the heater wattage of that unit).
It will either run at 100% with no change in output, then stop the output after about 10-15 seconds to reheat (for example with the old Martin Magnum 2000 unit) Or it will slow the output down to allow constant (but lower) output (like all machines produced since 1998).