MAMAC - Low Pressure Transducers
· 100%
solid state, micro-machined, glass-on-silicon,
ultra-stable capacitance sensor
· As
low as ± 0.05"wc (± 12.5 pa)
· Can
resolve less than 0.00001"wc (0.00025 pa)
· Up
to 10 PSID overpressure without zero shift
· Up
to 6 field selectable ranges in one unit
· Wide
12-40 VDC/12-35 VAC unregulated supply voltage
· Two
temperature compensated output versions, 4-20 mA
2-wire or field selectable 0-5 VDC/0-10 VDC
· Non-interacting
zero and span trimmers
· NIST
traceable calibration
· Two
rugged steel enclosure types NEMA 4 (IP-65) or
panel mount for ease of installation
· Short
circuit and reverse polarity protected
· Conforms
to EMC standards EN50082-1/EN55014/EN60730-1
The PR-274/275 incorporates a new micro-machined glass-on-silicon (Gl-Si)
capacitance sensor. This technology revolutionizes very low pressure
measurement. Temperature related zero drift, calibration shift due
to overpressure, non-repeatability, non-linearity, and extremely low
pressure sensitivity have been some of the problems which have
plagued the controls industry. The PR-274/275 with the new Gl-Si
technology not only addresses all of the above shortcomings, but for
the first time offers a reliable, accurate means to measure and
control building/room pressure, air flow, duct pressure, filter
pressure drop, or any other extremely low pressure application. Up
to six field selectable direct or compound ranges, two enclosure
types, field selectable outputs, fully temperature compensated NIST
traceable accuracy, non-interacting zero and span adjustments, short
circuit and reverse polarity protected output, and a liberal two
year warranty are some of the features which make the PR-274/275 the
industry's highest performance, ultra-stable, low pressure
transducer.
SPECIFICATIONS:
|
ACCURACY*:
± 1% FS
Maximum Pressure:
40 psig
Supply Voltage:
12-40 VDC 12-35 VAC (VDC output units only)
Supply Current:
VDC Units - 10 mA max. mA Units - 20 mA max.
Enclosure:
18 Ga C. R. Steel NEMA 4 (IP-65)
Finish:
Baked on enamel-PMS2GR88B
Conformance:
EMC Standards EN50082- 1(1992) EN55014(1993)/EN60730-
1(1992)
*Includes non-linearity, hysteresis and nonrepeatability
|
Compensated Temp Range:
0 °F -180 °F (-18 °C-82 °C)
T. C. Error:
±0.025%/° F (.03%/°C)
Media Compatibility:
Dry Air or Inert Gases
Port Connection:
1/4” Brass Hose Barb
Environmental:10-90%RH
Non-Condensing
Termination:
Unpluggable screw terminal block
Wire Size:
12 Ga max.
Load Impedance:3K
ohms max. at 40 VDC (mA output units) 1K ohms min. (VDC
output units)
Weight:
1.0 lbs. (.45 kg)
|
ORDERING INFORMATION: PR-

|
274 (enclosure)275 (panel mount) |
Rl
("wc) 0 T O 0. 10 / -0.05 TO + 0.05
R2
("wc)
0 TO 1.0 / 0 TO 0.5 / 0 TO 0.25/-0.5 TO + 0.5 / -0.25 TO +
0.25/-0.125 TO + 0.125 R3 ("wc) 0 TO 5.0 / 0 T O 2.5 / 0 TO 1.25/-2.5 TO +2.5 / -1.25 TO + 1.25/-0.625 TO + 0.625R4 ("wc) 0 T O 30 / 0 TO 15 / 0 TO 7.5/-15.0 TO + 15.0 / -7.5 TO +7.5/-3.75 TO + 3.75R5*(pa) 0 TO 25 / -12.5 TO + 12.5R6*(pa) 0 TO 250 / 0 TO 125 / 0 TO 62.5/-125 TO + 125 / -62.5 TO + 62.5/-31.25 TO + 31.25R7*(pa) 0 TO 1250 / 0 TO 625 / 0 TO 312.5/-625 TO + 625 / -312.5 TO + 312.5/-156.25 TO + 156.25R8 *(pa) 0 TO 7500 / 0 TO 3750 / 0 TO 1875/-3750 TO + 3750 / -1875 TO + 1875/-937.5 TO + 937.5 |
mA
(4-20 mA 2-wire) VDC (0-5 VDC or 0-10 VDC field selectable) |
Example:
PR-274-R2-mA:
Enclosure unit with R2
Range which has six (6) field selectable range options and 4-20
mA output.
The PR-274/275 incorporates
sophisticated integrated circuits to not only provide a high level, fully
conditioned and temperature compensated output, but also to offer field
selectable flexibility which was unheard of in the industry. The PR-274/275
offers up to six field selectable pressure ranges in one unit. In this way, a
customer does not need to know the exact pressure range prior to selection. By
merely knowing the application, a unit may be selected and then later field
configured for the desired pressure range. With fixed range units, in case of
engineering error or incorrect selection, the only solution is expensive field
recalibration or time consuming product exchange or replacement. Similarly,
numerous units have to be kept in stock as spares to cover all ranges in case of
field failure. The PR-274/275 with the field selectable pressure ranges in a
particular application thereby eliminating the need to stock numerous fixed
range units. (For a complete listing of all the ranges available, please see the
ordering information section on page three.)
On VDC output units, two additional field selectable options are available: dual outputs 0-5 or 0-10 VDC, and dual unregulated supply voltages 12-35 VAC or 12-40 VDC. By merely moving a shorting plug, one can select the desired output for the specific application. As far as supply voltage is concerned, the unit automatically configures for AC or DC and no field selection is necessary. Another feature is that the output is fully protected from short circuit to ground, or if the supply voltage is applied by mistake to the output. Past experience demonstrates that field related wiring problems do occur. Instead of denying this fact, the protection circuit is designed in to ensure trouble-free start-up. The VDC output unit is also designed to handle low impedance circuits. In fact, the unit can drive up to 1k ohms minimum. In this way, multiple controllers, indicators, or other devices can be paralleled to the output without performance degradation.
Automated NIST traceable
pressure controllers and precision Barocel® pressure sensors are
utilized to calibrate and certify the PR-274/275 transducers.
Calibration data on each unit is archived digitally for SPC and QC
purposes. All automated calibration systems are networked and data
is available on-line to numerous individuals at the same time. In
this way, extremely high standards of quality and calibration
integrity are maintained. Each unit is individually temperature
compensated in an environmental chamber. The temperature
compensation data is also digitized and archived for future
reference purposes. Compensating each unit individually ensures that
published specifications are adhered to.
Due to low mass of the micro-machined capacitance
Gl-Si sensor, the mounting orientation error for ranges higher than
1.0"wc (250 pa) is negligible. For extremely low ranges, if the unit
is installed as indicated on the label, there should be no
orientation error. However, due to space limitation, if the unit
cannot be installed in the indicted position, the error can be
easily removed by merely adjusting the zero trimmer. Since the zero
and span trimmers are non-interactive, adjustment to the zero should
under no circumstance affect the calibration integrity of the unit
including linearity and repeatability specifications across the
range.
The PR-274/275 is available with two packaging options: a NEMA 4 (IP-65) fully gasketed, dust proof and splash proof enclosure, or a lightweight but rugged panel mount chassis for ease of installation with minimum space requirement in a control panel. The NEMA 4 (IP-65) enclosure has an external mounting bracket to facilitate field installation. A 1/2" (.875"/22.25mm dia.) knock-out for conduit connection is also provided. A liquid tight cable connector is also supplied if the unit is not being hard wired. Once installed, the enclosure maintains its environmental rating and protects the electronics and the sensing element from condensation, corrosive contaminants and other environmental pollutants. Both packaging options also have additional features for ease of installation, including unpluggable terminal blocks,
rugged brass hose barbs, easily accessible zero and span trimmers, and conveniently located shorting plugs for field selection.