|Max. Recording Time:||9999 min., 59 secs. (167 hrs.)|
|Mm. Time Interval:||1 second|
|Stir Speed:||20 rpm|
|Operating Temps:||Std "Hot Pot" 150°F - 350°F (66° - 177°C) ±5% of setting StablTemp "Hot Pot" 140°- 350°F (61° - 177°C) ±1° of setting|
|Thermometer:||Stem Type: 5" Stem 50° - 500°F / 0° - 200°C|
|Electrical Requirements: (Specify)||110v/50Hz 300w or 220v/ 50Hz 300w|
|Dimensions:||7 1/2"L x 9"H x 5 1/2"W|
|Weight:||6 1/2 lbs.|
The Standard Gel Timer works on the principle that the stirrer drive motor stops when the gel state of the material under test puts a torque load on the stirrer in excess of the motor torque. The torque is consistent as long as the electric current supply is maintained (115V-60 Hz or 220V - 50 Hz).
The counter is geared to the motor and stops when the motor stops There is no adjustment of the synchronous motor torque as it is built into the motor by the manufacturer and will only run at a speed controlled by the frequency (Hz) of the electric current supply.
The torque tolerance for our acceptance of the motor is:
The lower value is checked on each motor and is accomplished by the motor with drive shaft (3/8” dia) lifting a 120 gram weight via a thread wrapped around the shaft. Motors too weak for this test are discarded. Motors lifting 150 grams are too strong, but can be adjusted for lower torque.
In the new timers, it still uses the synchronous motor, but the time is sensed via a crystal controlled digital timer coupled optically to the motor and circuited so that the timer stops only when the motor stops. Then this timer always reads real time regardless of the length of cure.
Consistency of test results is probably more influenced by the temperature of the resins, the resin/hardener ratio, the total amount of material for the test, than by the variability of the gel timer.