Bel-2000 Gen II
Q. Why does My Unit lock up ?
A. If the battery is not taking a full charge then it will not put out enough current to run on the system. Generally it is recommended that new
batteries are installed every 6-months, depending on how much the unit
is used and how many times the battery has been recharged. If spare
batteries are left on the shelf they should be uncharged. The battery should
be charged for a minimum of 3.5 hours just prior to use.
Rho-Meter
Q. Why do the Rho-Meter readings and the Bel-2000 readings differ so much?
A. Due to the way the Bel-2000 and the Rhometer process their impact signals to Rho-Values, a difference of "RHO" values should also be referenced with the type of instrument it was taken with.
The Bel-2000 takes the peak force signal by way of a transducer in the hammer head, where as the Rho-meter take the force signal by way of an accelerometer at a specified and present amount of drop distance. There is more room also for operator error with the Bel-2000 unit. It is important also to pay special attention to the warning "Beeps" on the Bel unit to tell the operator if they are hitting the roll too hard or too soft, this curcuit is meant to help the operator determine how hard to tap the roll.
I strongly recommend taking a good know roll, and taking several hits across the roll, then do a bad roll and record the readings and the instrument used. The Rho numbers may need to be adjusted up or down if switching from a Rho-meter to a Bel-2000 or vice versa. They will both give the same information and tell the operator that their machinery may need some adjustment.
Q. Why Do I need to recalibrate the Rho-meter once a year?
A. With a lot of use the original setting of drop height can change enough to effect the readings on the unit. The circuitry in the Rho-meter is aligned to very tight parameters by the technician before the unit is shipped and the drop heigth is set to a specific distance to give the correct amount of impact to the roll. If the distance over time changes ever so slightly then the readings will be off. When a unit is sent in for recal and recert, both the electronics are tested and aligned if necessary and the drop distances are all re-checked and re-set to the original settings to give accurate Rho readings to + or -2 Rho. Also checked are the spring tensions inside the unit to look for a difference in tension. The calibration blocks are also checked at a specific temperature with the use of several Rho-meters including the master Rho unit. The blocks can give and change hardness values over time.
Q. Why does my Rho-meter keep telling me it has a "Lo Batt" when I just charged it?
A. If the battery is old, and has seen a lot of use and recharging, then it may be time to charge it. The battery may show that it is taking a full 28 volt charge, but may discharge rather rapidly, this is an indication that the cells have chemically broken down and will not hold as charge.
If a battery is charged for more than the recommended 8 hours max charge time, then the cells will break down and the battery again will not hold it's charge. The cell plates have chemically been destroyed by over charging. Also charging a Rho-meter battery with a power supply is not recommended due to the possibility of putting too much current through the battery and destroying the cells. These batteries must be charged with the proper charger with the proper voltage and current as well as charge time. Charging the battery too fast can cause it to break down quicker and will have a shorter life.