Specifications

Pressure Ranging
Each standard Series 7116B Spirahelic
®
Pressure Indicating
Transmitter is factory calibrated to produce 4 mA at zero scale
reading and 20 mA at full scale reading. The following procedure
should be used if the pressure versus output signal relationship
needs to be checked.
1. With the unit connected to the companion receiver per pre-
ceding instructions, insert an accurate milliammeter, with a full
scale reading of approximately 30 mA, in series with the cur-
rent loop. A controllable pressure source capable of achieving
the desired range should be connected to the pressure port
of the transmitter and teed into an accurate reference pres-
sure gage or manometer. The instrument must be ranged in
the same position in which it is going to be used. Vertical
mounting is recommended.
2. Apply electrical power to the system and allow it to stabilize
for 10 minutes.
3. With no pressure applied to the transmitter, adjust “Zero”
adjustments so that loop current is 4 mA.
4. Apply full range pressure and adjust loop current to 20 mA
using “Span” adjustments.
5. Relieve pressure and allow transmitter to stabilize for 2 min-
utes.
6. Zero and Span adjustments may be interactive so repeat steps
3 thru 5 until zero and full range pressures consistently pro-
duce loop currents of 4 and 20 mA respectively.
7. Remove the milliammeter from the current loop and proceed
with final installation of the transmitter and receiver.
MAINTENANCE
No lubrication or periodic servicing is required after final installation
of the Series 7116B Spirahelic
®
Pressure Indicating Transmitter. A
periodic check of calibration is recommended following the pro-
cedure under pressure ranging and pneumatic calibration test.
Except for this, these transmitters are not field serviceable and
should be returned, freight prepaid, to the factory if repair is need-
ed. Be sure to include a clear description of the problem plus any
application information available.
Repairs
Field repair should not be attempted and may void warranty.
Gages needing calibration or other service should be returned pre-
paid to :
Dwyer Instruments, Inc.
ATTN: Repair Department
102 Indiana Highway 212
Michigan City, IN 46360
Multiple Receiver Installation
An advantage of the standard 4-20 mA DC output signal used in
Series 7116B Spirahelic
®
Pressure Indicating Transmitters is the
compatibility with a wide range of receivers. Devices such as the
A-701 Digital Readout, A-702 Digital Readout with alarms, an ana-
log panel meter, a chart recorder and other process control equip-
ment can be operated simultaneously. It is only necessary that all
devices be designed for a standard 4-20 mA input, the proper
polarity of input connections must be observed and the combined
receiver resistance's must not exceed the maximum for the current
loop. If the receiver indicates a negative or down scale reading, the
signal input leads are reversed.
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