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Manual 111-082010_Nall Mass Flowmeters Page 21 of 23
11.0 Accessories
OPTIONS AND ACCESSORIES
11.1 Double Point Relay Flowmeter/Alarm (DNALL-P):
The Hastings Flowmeter/Alarm is a complete Linear Mass Flowmeter with all of its characteristics and
ranges. It also includes two adjustable HI-LO set points which can be read on the digital indicator. When
the flow rate exceeds the pre-set LO alarm point, the LO relay is energized; then its normally closed (NC)
contact opens and the normally open (NO) contact closes. This sequence also occurs when the flow rate
exceeds the pre-set HI alarm point. The SPDT relays de-energize and return to their normal state when the
flow rate drops below the pre-set alarm points. The relays are rated 5 amps @ 115 VAC.
11.2 Totalizers (TNALL-P):
11.2.1 Descriptions
The Hastings Mass Flow Totalizer is an electronic/mechanical device which, when used in conjunction
a. Specifications: (For Totalizer Only)
1 Accuracy: 25BC and 115 K 15 VAC K ½% F. S.
1 Count Rate: 5, 10, 50 & 100 Counts/Min. @ F. S. Flow –selectable by use of the front panel
switch.
1 Power: 115 volts AC 50-60 Hz, 10 watts.
b. Circuits
The circuit for the Totalizer is a voltage to frequency converter which produces a pulse rate linear
proportional to the 0-5 volts DC input signal. The pulse rate is set by the factory on standard units for 5, 10,
50, and 100 counts/min. Any of the four ranges can be selected with the Range Selector switch on the front
panel or by changing a jumper on the back panel on some models. Normally ranges are 5 cpm or 50 cpm for
a 5, 50, 500, 5K, or 50K SCCM range. 10 cpm are used for a 10, 100, 1K, or 10K SCCM range. Other
count rates up to 1000 counts/min. are available on special order.
Special count rates are optional when the range of the flowmeter does not correspond to the factor of 5 or 10.
c. Counter
The pulses from the Totalizer circuit are accumulated by the six-digit electro-mechanical counter. The
counter recycles automatically at 999,999 or can be manually reset to zero at any time.
11.2.2 Mounting
The Hastings Mass Flow Totalizer is normally built into a NIM style Hastings Mass Flowmeter power
supply. The meter is designated by the prefix T.
11.2.3 Totalizer Sensitivity
The Totalizer count rate varies in direct proportion to flowmeter output variations. Therefore, the total
number of counts over a period of time can be realted to the total flow for that period by determining the
sensitivity of the flowmeter/Totalizer combination. The sensitivity is the full-scale count rate of the
Totalizer.
Example: A TNALL-P Flowmeter with an HS-10S transducer is used with the Range Selector set for 100
cpm over a period of 7 hours, and a total of 13,500 counts accumulate on the counter.