Model 33

Pneumatic Transmitters
Model 33 Nullmatic™ Temperature Transmitter
Introduction
Features & Benefits
Rugged design ensures operation in the harshest environments
Powder coating provides corrosion resistance
Wide ranges of temperature spans and temperature ratings
provides application versatility
Description
Model 33 Nullmatic Temperature Transmitters measure
temperature to 1400°F (760° C), with measured spans as small
as 50° or as large as 1000°F. Moreover, the Model 33
employs a pilot-operated null-balance principle or operation,
which maintains the output pressure regardless of wide
changes in flow or supply pressure. As such, they provide
temperature measurements and transmit a pneumatic output
proportional to the measured temperature range for vessels,
reactors, fractionating columns, heat exchangers, pipelines,
air ducts, and flues.
Each Model 33 includes a helium-filled thermal system and a
Nullmatic force-balance transmitter. The force-balance transmitter
converts pressure changes in the thermal system caused by
changes in temperature to 3-15 psig output signals proportional to
the measured temperature range. The thermal system includes a
bulb with a bendable extension, a flexible armored capillary, and a
bellows. Three kinds of bulbs are available for use with a thermal
system and all are made of 316 stainless steel or copper.
A circuit maintains a constant differential-pressure-drop across
the nozzle with the differential determined by the force of the
spring under the diaphragm. This maintains the transmitter’s
total internal bellows movement within 0.001", which ensures
that it is accurate under virtually any condition and it
minimizes hysteris and non-linearity errors.
Specifications
Temperature Span1
3/4" O.D. and averaging bulbs
Minimum: 50°F (30°C)
Maximum: 1000°F (540°C)
3/8" O.D. Bulbs
Minimum: 70°F (40°C)
Maximum: 1000°F (540°C)
Operating Temp. Limits
3/4" O.D. and averaging bulbs
Minimum: -450°F (-270°C)
Maximum: 1400°F (760°C)
3/8" O.D. bulbs
Minimum: -450°F (-270°C)
Maximum: 1000°F (540°C)
Maximum Bulb Operating Temperature2
Bulb Size: 3/4 x 4"
Copper: 800°F (427°C)
SS: 1400°F (760°C)
Bulb Size: 3/8 x 4"
Copper: 800°F (427°C)
SS: 1000°F2 (540°C)
Minimum Bulb Operating Temperature
-450°F (-270°C)
Supply Pressure
Normal: 20 psig (3-15 psi output)
Maximum: 35 psig
Minimum: 4 psi above maximum output
8
Output Pressure
3-15 psig (within 1%3)
Output Range
3–15 psig
3-27 psig and 0-30 psig output ranges are available
Connections
1/4" NPT for supply and output
Ambient Temp. Limits
-40 to 180°F (-40 to 82°C)
8.19
Pneumatic Transmitters
Model 33 Nullmatic™ Temperature Transmitter
Technical data
Order No.
Response level
Model Number
within 0.01% of full scale
Basic Transmitter Model Number
33■ ■ ■
▲ ▲ ▲
Air consumption (with 20 psi supply)
less than 0.08 scfm in balanced condition on dead-end
service
Speed of Response4,5 (with transmitter coupled through
100 ft. of 1/4" OD tubing to receiver – element immersed in
agitated water)
Bare SS bulb: 0.03 minutes
3/8" SS bulb in SS well: 0.3 minutes
3/4" OD SS bulb in SS well: 0.7 minutes
Ambient Temperature Effect (max. change in output
for -50°F change in ambient temperature) less than 1% of
full-scale shift on most ranges
Designator for Mating Transmitters
and Thermal Systems
• Spans of 250 to 1000°F
• Spans of 150 to 800°F
• Spans of 100 to 475°F
• Spans of 70 to 250°F
• Spans of 50 to 70°F
C
A
C
D
E
SE
Thermal System Number
Thermal
System Bulb
Bulb
Material Diameter Type
Copper
Copper
316 SS
316 SS
316 SS
316 SS
316 SS
316 SS
Copper
316 SS
316 SS
Copper
316 SS
Copper
316 SS
316 SS
3/4"
3/4"
3/4"
3/4"
3/4"
3/4"
3/4"
3/4"
3/4"
3/16"
3/8"
3/8"
3/8"
3/8"
3/8"
3/8"
Factory Code
Bulb
Bulb
Bendable Armored
Overall Active Extension Capillary
Length Length Length
Length
Plain
4"
Rigid
6"
Plain
4"
Rigid
6"
Plain
4"
Non-Rigid 4"
Plain
4"
Rigid
6"
Non-Rigid 4"
Extendable 14"
Plain
4"
Plain
4"
Rigid 11-1/4"
Rigid 11-1/4"
Plain
4"
Plain
4"
4"
4"
4"
4"
4"
4"
4"
4"
4"
14"
4"
4"
4"
4"
4"
4"
20"
None
20"
None
20"
20"
20"
None
20"
20"
24"
24"
None
None
24"
24"
36"
36"
36"
36"
36" PVC
36"
120"
120"
36"
36"
36"
36"
36"
36"
36" PVC
120"
5012
5048
5072
5079
5081
5098
5142
5257
5287
5341
5475
5476
5477
5478
5479
5580
(C7C)
8
1) Certain spans can be used to 1400°F with factory approval.
2) Materials contacting process fluid – stainless steel standard bulbs and wells; special materials available at extra cost. Metallic materials can be ordered to
conform with NACE standard MR-01-75 (1980 Revision).
3) Instruments which have been calibrated to within ½% are available, at extra cost.
4) With 500 ft. transmission line, lag times will increase approximately 0.07 minutes.
5) These time constants are the lag times required for 63.2% response.
8.20
Pneumatic Transmitters
Model 33 Nullmatic™ Temperature Transmitter
Technical data
TABLE 1
Fahrenheit Selection
Maximum Operating Temperature °F 1,2,3
Model
Bulb
Dia.
Com.
Spans °F
50
60
70
80
90
100
110
120
125
130
140
150
160
170
175
180
190
200
225
250
275
300
325
350
375
400
425
450
475
500
600
700
800
900
1000
33A
3/8"
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
260
330
400
480
550
620
700
770
840
890
940
1000
1000
1000
1000
1000
33C
3/4"
Aver
3/8"
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
255
325
400
470
540
610
680
750
820
890
960
1230
1300
1400
1400
—
—
—
—
—
—
—
—
—
—
—
—
150
190
230
250
270
305
340
440
500
550
610
665
715
765
820
870
920
970
1000
—
—
—
—
—
33D
3/4"
Aver
3/8"
—
—
—
—
—
—
—
—
—
—
—
150
190
230
250
270
310
350
450
550
650
750
850
950
1000
1125
1215
1285
1380
1400
1400
1400
1400
—
—
—
—
—
—
—
100
150
200
225
250
300
350
400
440
460
470
500
520
580
640
700
750
810
870
920
980
—
—
—
—
—
—
—
—
—
Maximum Overrange °F
33E
3/4"
Aver
3/8"
—
—
—
—
—
100
165
220
250
280
335
395
450
510
540
565
620
680
825
970
1000
1000
1000
1000
1000
1400
1400
1400
1400
—
—
—
—
—
—
—
—
150
200
230
270
290
320
330
360
390
430
450
480
500
520
540
570
640
700
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
33SE
3/4"
Aver
—
—
—
200
286
370
465
550
590
635
720
805
890
975
1000
1000
1000
1000
1000
1000
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
3/8" Bulbs
(copper bulb limit - 800°F)
3/4"
Aver
33A
33C
33D
33E
100
250
370
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
650
750
850
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
—
—
—
—
—
—
—
—
—
—
—
650
710
770
800
830
890
950
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
—
—
—
—
—
625
900
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
—
—
—
—
—
—
650
825
975
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
—
—
—
—
—
—
—
—
—
—
* All 316 SS, 3/4",
Aver - 1400°F
All Cu. 3/4" - 800°F
1) Maximum operating temperature for Copper Bulbs is 800°F.
2) Transmitter must be selected from first column (read left to right) of maximum operating temperatures which satisfy range requirements.
3) Thermal systems are not interchangeable between different lettered transmitters.
8.21
8
Pneumatic Transmitters
Model 33 Nullmatic™ Temperature Transmitter
Technical data
TABLE 2
Celsius Selection
Maximum Operating Temperature °C 1,2,3
Model
Bulb
Dia.
Com.
Spans °C
28
30
35
40
45
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
225
250
275
300
350
400
500
556
33A
33C
33D
Maximum Overrange °C
33E
3/8"
3/4"
Aver
3/8"
3/4"
Aver
3/8"
3/4"
Aver
3/8"
3/4"
Aver
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
155
185
210
240
265
320
390
450
500
540
540
540
540
540
—
—
—
—
—
—
—
—
—
—
—
—
—
—
125
155
185
210
240
265
295
365
435
505
535
680
700
760
—
—
—
—
—
—
—
—
—
—
95
130
165
205
240
265
285
305
325
345
365
400
450
495
535
—
—
—
—
—
—
—
—
—
—
—
—
—
—
95
135
175
215
255
295
335
375
415
455
495
535
600
700
750
760
760
760
—
—
—
—
—
—
—
—
60
105
155
200
245
265
295
315
335
360
385
405
430
455
475
—
—
—
—
—
—
—
—
—
—
—
—
—
—
65
125
185
240
300
355
415
470
530
540
540
540
540
540
540
760
760
760
—
—
—
—
—
—
—
—
70
90
110
140
170
205
240
270
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
90
140
225
310
395
480
540
540
540
540
540
—
—
—
—
—
—
—
—
—
—
—
—
—
—
33SE
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
3/8" Bulbs
(copper bulb limit - 425°C)
3/4"
Aver
33A
33C
33D
33E
35
40
120
190
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
390
455
540
540
540
540
540
540
540
540
540
540
540
540
—
—
—
—
—
—
—
—
—
385
445
510
540
540
540
540
540
540
540
540
540
540
540
540
—
—
—
—
—
—
—
—
—
—
—
380
480
540
540
545
540
540
540
540
540
540
540
540
540
540
—
—
—
—
—
—
—
—
—
—
—
380
450
525
540
540
540
540
540
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
* All 316 SS, 3/4",
Aver - 760°C
All Cu. 3/4" - 425°C
8
Options & Accessories
Compression fitting 3/4" bulb NPT Connection
Compression fitting 3/4" bulb for Thermowell
(P/N 1551-31)
Compression fitting for 3/8" bulb – Tapped Exhaust
(P/N 12140-3 )
Bracket to Mount Transmitter to Thermowell (P/N 859-89 )
Kit for 2" Pipe Mounting (P/N 3351-101 )
Plastic Cover for Transmitter (P/N 3351-94 )
1) Maximum operating temperature for Copper Bulbs is 425°C.
2) Transmitter must be selected from first column (read left to right) of maximum operating temperatures which satisfy range requirements.
3) Thermal systems are not interchangeable between different lettered transmitters.
8.22
Pneumatic Transmitters
Model 33 Nullmatic™ Temperature Transmitter
Dimensional drawings
Mounting Dimensions
8
8.23