Information for standard AWG (American wire gauge )
|Gauge||Diam||Area||R||I at 3A/mm2|
Storage: Batteries transportation and storage should be in discharged condition. Do not store and use Ni-Cd, Ni-MH or Li-ION batteries in metal containers.
When store charged battery it's capacity decreases with time, at low temperature they became flat faster.
Do not expose batteries (work or storage) to heat, moisture or chemically active environment.
Do not operate or store batteries if risk of "short" circuit between poles.
Do not charge Ni-MH batteries in devices for Ni-Cd, except if both types supported by charger .
Battery usage: Before use the batteries please, charge/discharge them repeatedly with the appropriate current for the capacity (or after installation, if soldered in packs).
Ni-Cd or Ni-MH?: Ni-MH batteries have discharge time longer than Ni-Cd, in the same capacity.
Li-ION batteries: Most compact, provide higher voltage per cell, quick charge, higher discharge current, longer time for storage the capacity , less toxic for recycle, short life than Ni-Cd/Ni-MH (cycles).
Memory effect : Ni-MH and Li-ION batteries have no "memory effect" - can be charged fully from any level (no need to be discharged before) . This increase their lives reducing the usual number charge/discharge cycles .
Ni-Cd batteries have the effect of "memory" - if Ni-Cd cell is being discharged to a certain capacity (eg 50% of nominal), it possibly would not work under this level, even if powered device can operate at lower current (eg 20% of battery power).
Many users treated above batteries as "destroyed". Usually if apply one or two cycles of charge/discharge up tp 1VDC solves the problem and then the calle can be charged full charge again with deep discharge cycles .
This well known solution is usually difficult for the battery cells in packs. Users simply exchanged the cells with lack of power or whole pack treated as flat.
These cells in the package usually drop first, drawing charge from the next cells, which leads to a decrease capacity of the entire pack. Therefore, these batteries (packs) are recommended for use with cycles of full discharge.
Installation : When in pack (Ni-Cd, Ni-MH) do not let battery cells overheating by soldering. It make changes in chemical substances and cause low battery life.
In batteries without leads (Ni-Cd, Ni-MH, Li-ION) should use quick "point" soldering. If do solder directly onto battery tops the user risks to destroy the cell.
Do not use cells (Ni-Cd, Ni-MH) with different capacities in the same pack.
Charge precautions: Observe time charge, if not provided by the charger.
Do not charge/discharge the cells with devices not suitable for exact type of battery (pack)
Recommended charge current: 0.05 to 0.1 of battery capacity.
Recommended trickle charge current: 0.03 to 0.05 of battery capacity.
Recommended discharge current: 0.2 of battery capacity.
Thermal protection- build protection for range of 70 ~ 100 ° C.
It's better to use battery powered units with automated switch-off function (by Ni-Cd, Ni-MH) - Single cells-if voltage drop below 1V (Pack- 1V multiplied by the number of cells), Li-ION 2.8V.
If consumption continuous squeeze the battery it can decrease voltage to 0 and the partially change the polarity of the battery - after this the battery is destroyed.
Please remember! Evading above details lead to shortening battery life. Usage in heated area caused changes in chemistry of cells, active mass leakage through valves, dry plates, oxidation of poles or burst!
When you measure VAC is important to know the value measuring principle : the highest, average, RMS "root-mean-square" or the other.
1 m3/min = 0.5885 ft3/sec = 35.31 CFM
Air pressure N / m (Pa)
1 N/m = 1Pa = 0.004 inch H2O = 0.10197 mmH2O = 0.00001 AFM
Resistance Temperature Detectors / RTD / RTDs
Resistance Temperature Detectors (RTD), as the name implies, are sensors used to measure temperature by correlating the resistance of the RTD element with temperature.
Most RTD elements consist of a length of fine coiled wire wrapped around a ceramic or glass core.
The element is usually quite fragile, so it is often placed inside a sheathed probe to protect it.
The RTD element is made from a pure material whose resistance at various temperatures has been documented.
The material has a predictable change in resistance as the temperature changes; it is this predictable change that is used to determine temperature.
Common Resistance Materials for RTDs:
Platinum (most popular and accurate)
Class AA (Formerly 1/3B) = ±(0.1+0.0017*t)°C or
100.00 ± 0.04Ω at 0°C
Class A = ±(0.15+0.002*t)°C or 100.00 ± 0.06Ω at 0°C
Class B = ±(0.3+0.005*t)°C or 100.00 ± 0.12Ω at 0°C
Special class not included in DIN/IEC60751:
Class 1/10B = ±1/10 (0.3+0.005*t)°C or
100.00 ± 0.012Ω at 0°C