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Helpful Operation Tips
Zero Adjustment
The Zero Adjust screw must be turned in the direction opposite to the correc-
tion required in the Pointer reading. For example, if the Pointer needs to move
clockwise to "1.000" on the scale, turn the Zero Adjust screw counterclockwise.
After making adjustments, allow the Pointer to stabilize.
Response Time
When measuring gas at the normal flow rate of 12 SCFH, the response time to
reach the final reading is 40–45 seconds. To reduce this time, you can operate
at a higher flow rate. This can be done by adjusting the Flowmeter Valve so
that the float reads higher than the actual gas relative density.
Over-Pressure Protection
If the Flowmeter Valve is opened before the Selector Valve is turned to "LG" or
"HG", the valve cover will lift off the body of the instrument to relieve the pres-
sure and will be reseated by the spring.
Purging to 1.000 After Measuring a Gas
The Gravitometer must be purged to bring the Pointer within the range of the
Pointer Lock mechanism. If the Pointer starts toward "1.000", and then hesi-
tates and remains at an intermediate reading, turn the Selector Valve halfway
beyond zero ("0") towards the next position. If the Pointer then continues
forward and reaches "1.000" check for an obstruction as described in the "Air
and Gas Flow Checks" Diagnostic Flowchart in Chapter 4.
3-4 | 388 Ranarex Portable Gas Gravitometer – Chandler Engineering
During normal operation, the Zero Adjust screw requires less than 1/4
turn to set the Pointer to "1.000". If more than 1/2 turn is ever required,
stop the motor and investigate the cause.
Never turn the Zero Adjust screw to the limit of the adjustments, clock-
wise or counterclockwise, with the motor On.
PN RI-212, Rev. L
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