多路智能巡檢打印記錄儀     　　多路智能巡檢打印記錄儀 采用先進的微處理器進行智能控制，集多路測量顯示控制及打印記錄于一體。本機包含多路智能巡檢控制儀的全部功能，增加了現場打印記錄功能，可自動定時打印或隨機打印各支路的測量值。 　　各輸入端口均具備萬能信號輸入功能，且各路可同時輸入不同類型的信號，只需通過儀表菜單的簡單選定，即可實現不同類型輸入信號（各種熱電偶、熱電阻、標準電壓 / 標準電流信號）之間的輕松切換，提高了儀表的通用性和可靠性。 　　控制輸出有二種：各路統一報警輸出 / 變送輸出；各路分別獨立報警輸出 / 變送輸出。統一報警型又分為：報警記憶型（任一支路報警未解除將一直報警，直至所有各路均無報警）；報警無記憶型（巡回至有報警的支路時輸出報警，巡回至無報警的支路時則不報警）。輸入/輸出回路均采用光電隔離，抗干擾性能強。 　　具有高亮度LED數碼顯示和大屏幕全中文LCD液晶顯示兩種。可帶有串行通信接口。具有臺式和卡入式二種外形供選擇。 　型 號 WP-RD、RMD806、807、808、809、816、828系列   輸入信號 模 擬 量　　1～28路巡回測量 模 擬 量　　熱電偶：標準熱電偶 — B、S、K、E、J、T、WRe等 　　　　　　電　阻：標準熱電阻 — Pt100、Cu50、Cu100 　　　　　　遠傳壓力電阻 —　30Ω～350Ω等 　　　　　　電　流：0～10mA、4mA～20mA等(輸入電阻≤250Ω) 　　　　　　電　壓：0～5V、1V～5V、mV等(輸入阻抗≥250KΩ)   輸出信號 模擬量輸出　DC 4mA～20mA (負載電阻≤500Ω)　　DC 0～10mA (負載電阻≤750Ω) 　　　　　　DC 1V～5V (負載電阻≥250KΩ) 　　　DC 0～5V (負載電阻≥250KΩ) 開關量輸出　繼電器控制輸出 — ON/OFF帶回差 　　　　　　觸點容量：AC 220V/3A；DC 24V/5A(阻性負載) 　　　　　　可控硅控制輸出 — SCR(過零觸發脈沖)輸出，　　AC 400V/0.5A 　　　　　　固態繼電器輸出 — SSR(固態繼電器控制信號)輸出， DC 5V～24V/30mA 通訊輸出　　標準串行雙向通訊接口：　通訊協議：RS-232C、RS-485 　　　　　　波特率 — 300～9600bps (自由設定) 饋電輸出　　DC 24V，負載≤30mA   特 性 測量精度　　±0.2%FS±1字或±0.5%FS±1字 分 辨 率　　±1字 顯示范圍　　-1999～9999 顯示方式　　高亮度LED數碼顯示　　發光二極管工作狀態顯示 　　　　　　當前日期及時間顯示 1～28路測量通道號顯示 　　　　　　四位（-1999～9999）　測量值/設定值顯示 通道屏蔽與鎖定顯示 控制報警　　可選擇1～28路統一上限、下限控制/報警輸出，LED指示。 溫度補償　　0～50℃溫度自動補償 打印控制　　配接微型打印機，可自動定時打印或手動即時打印 參數設定　　面板輕觸式按鍵數字設定　　參數設定值斷電后永久保存 　　　　　　參數設定值密碼鎖定 保護方式　　熱電偶/熱電阻輸入斷線報警 　　繼電器輸出狀態LED指示 　　　　　　輸入超／欠量程報警 電源欠壓自動復位 工作異常自動復位   使用環境 環境溫度　　0～50℃ 相對濕度　　≤85% RH　·避免強腐蝕氣體 供電電壓　　常規型　　·AC 220V +10%-15%（50Hz±2Hz，線性電源） 　　　　　　特殊型　　·AC 90V～265V (開關電源)　·DC 24V±2V (開關電源) 功　　耗　　≤10W（AC 220V線性電源）

型 號 WP-RD、RMD806、807、808、809、816、828系列 WP-RD、RMD806、807、808、809、816、828系列 儀表外形 　 　 　 　 外形尺寸 寬×高×深：360×140×240mm 寬×高×深：160×80×140mm×2臺 開孔尺寸 （mm）     重 量     接 線 圖

選型表

香港上潤精密儀器有限公司產品選型目錄

WP-D831-80－08-N；
WP-S833-01－12-3H
WP-8K-91-T03E8220-T
WP-LS801-01-A-HL-P  
WP-C403-01-12HL-W 
WP-C403-02-12-HL    
WP-C803-01-12-HL     
WP-c803-01-12-HL-p     
WP-C801-00-08-N
WP-C403-01-12-HL 
WP-T804-81-08-2H2L
WP-D821-000-2323－N
WP-D823-011-0808-HL
WP-D831-80－08-N
WP-S833-01－12-3H
WP－D806－02-23－N-T
WP－MD832－81-23－HL－T
WP－CDA03－82-23－HL-P
WP-XTRM-11-10
WP-XTRM-11-15
WP-XTRM-12-10
WP-XTRM-13-10
WP-XTRM-14-20
WP-X803-0-A
WP-X803-2-B-T
WP-KS805-022-0312-P-T
WP－TX825－812－1212－HL－T
WP-P805-010-08-HL
WP-P905-820-12-HL-P-T
WP-D855-012-03-HL
WP－TX865－82－12－T
WP-C875-012-12-HL
WP－RD803-22-23－HL-T-F
WP-LEQN-111180HL

WP-LEDV-C600NT(300V/300V)
WP-LEDV-T282HLT(1000V/100V)
WP-LEAP-C600NT(400V,5A）
WP-LEAQ-T282HLT(380V/380V,5A/5A）
WP-LEPQ-C100NT(500V/100V,100A/5A)
WP-LEPQ-T282T（220V/220V,5A/5A）
WP-LE3PQ-C1004NT(500V/100V,100A/5A)
WP-LE3PQ-T2824NT（220V/220V,5A/5A）
WP-LE3V-C2804-3HT(400V/400V)
WP-LE3A-C 280-3HT(100A/5A)
WP-LE3P-C1004HLT（380V/380V,100A/5A）
WP-LE3Q-C2004HLT（380V/380V,100A/5A）
WP-LEMQ-C1004HLT（380V/380V,100A/5A）
WP-LEMQ-C1004HLT（380V/380V,100A/5A）
WP-LECJ-L1824H0T
WP-LEHz-C600N(220V)
WP-LEPF-C200NT（380V/380V，100A/5A）

WP-101TC20-03(0～1000℃)
WP-201-TC224-03
WP-202-TC220-0303 (0～1300℃)
WP－202BA22－1212
WP-D807-81-10-HH-K-T
WP-K1A1D1G1FEA5G
WP-D401-02-08-N
WP-L801-20-F-N-P
WP-L803-01-FAG-HL-2P
WP-K1A1S1G1FEA5G
WP-8K-11-T23E000
WP-C801-00-12-N-P
WP-D821-000-0308-NN
WP-GP6E12M1B1D1ND5
WP-LQ802-02-ANGN-HL-P
WP-D805-012-12-HL-P
WP-S805-012-08-HL-P
WP-S805-012-04-HL-P
WP-C803-02-08-HL-P
WP-C803-02-12-HL-P
WP-LQ804-02-ANGN-HL-P
WP-B803-0-A
WP-T823-011-1212-2H2L-2P
WP-C803-01-03-HL-T
WP-S803-01-08-HL-T
WP-D803-01-12-HL-T
WP-L801-02-A-HL-T
WP-S821-822-1919-NN-2P
WP-D821-800-1908-NN-P
WP-8K11T12E020P
WP-C803-03-08-HL-P
WP-C403-01-12-HL-P
WP-D835-822-1212-H-R
WP-C803-81-12-HL-P
WP-T805-012-12-HL-P
WP-C401-00-15-N-W
WP-L801-02-F-N-P
WP-C803-01-12-HL-P
WP-8K11T23E000
WP-D805-020-12-HL-P
WP-D806-80-08-N
WP-T805-010-12-HL
WP-LEAVC600NT
WP-LEAAC600NT
WP-D824-80-08-NN
WP-201IC22-I
WP-B803-0-A
WP-T805-010-12-HL
WP-Z901-088-18-N
WP-8AS1G1F2A5G37
WP-L801-00-A-N-P
WP-L802-00-AAG-N-P
WP-C803-06-23-HL
WP-B803-01-A
WP-LCS1FA14F2A5Z/0-2.5m
WP-C903-02-23-HL-P
WP-C904-01-23-2H2L-P
WP-D816-01-23-HL
WP-LC1S3YA1F2A5H/0-5M
WP-LDS1FA1F2B5G12/0-160KPa
WP-D816-81-08-HL-T
WP-D805-87-08-HL-T
WP-L801-01-ANN-HL-P-T
WP-L801-02-ANN-HL-P-T
WP-L801-01-AGN-HL-P-T
WP-T835-080-1818-H-P
WP-S403-01-12-HL-P
WP-L801-01-ANN-HL-P
WP-R80A-1040100A
WP-T805-022-23-HL-P
WP-T825-012-1212-H-P
WP-L901-01-A-BN-P
WP-S403-01-12-HL-P
WP-S405-020-12-HL-P
WP-D808-01-08-HL
WP-S835-012-1212-H-R-M-2P
WP-L803-02-AAA-HL-2P-T
WP-D808-01-08-HL
WP-L801-01-F-HL-P
WP-L801-02-FNN-HB-P
WP-8AS1G1F2A5G37/-100-400KPA
WP-8AS1G1F2A5G34/-0.1-0MPA
WP-C404-01-09-2HL
WP-C801-02-03-N
WP-8K-11T12E020P
WP-D423-011-0909-LHH
WP-LC1S3YA1F2A5H/0-35KPa
WP-R80A1144000A
WP-C803-01-23-HL
WP-D816-01-23-HL
WP-R80A1144000A
WP-C804-01-23-2H2L-P
WP-C803-01-23-HL-P
WP-L802-01-AAG-HL-2P
WP-T803-01-23-HL-P
WP-S805-022-23-HL
WP-D935-060-1212-H
WP-B803-0-A
WP-AKCS1G1FIC2G17G/0-1MPA
WP-D823-011-1414-2H2L-2P
WP-K1A1S1G1FEB5G/0-6MPA
WP-AKCS1R1FIC5G29G/-9-0KPA
WP-AKCS1R1FIC5G10G/0-50KPA
WP-AKCS1R1FIC5G30G/-20-0KPA
WP-L802-01-AAG-HL-2P
WP-C803-01-23-HL
WP-T803-02-23-HL
WP-LEAV-C600NT
WP-T803-01-12-HL-P
WP-T803-01-12-HL
WP-L801-02-ANN-LL-P
WP-C403-01-12-HL-P
WP-L801-00-F-N
WP-D923-011-2323-HL
WP-C903-01-23-HL-P
WP-C903-01-23-HL
WP-C903-02-12-HL-P
WP-LS801-02-ANN-LL-P
WP-C803-01-03-HL
WP-D923-011-2323-2H2L
WP-C904-01-23-2H2L-P
WP-TS803-01-12-HL-P
WP-DP3E22B3D0S5/-4~0KPa
WP-三閥組
WP-8AS1G4F2A5G/0~40MPa
WP-BGP8E22M1B1D2JS5/0~10MPa
WP-R80B2004000A
WP-D423-011-1010-HH-P-W
WP-L803-02-AAG-NN-2P
WP-L802-02-AAG-NN-2P
WP-C901-00-02-N
WP-C801-00-04-N
WP-8K-11-T23E000-T
WP-8K-11-T23E000-T
WP-8K-12-T23E040P-T
WP-L801-02-ANN-NN-P-T
WP-8K-12-T23E040P-T
WP-B803-0-A
WP-PS805-022-12-NN-P-T
WP-101TC20-02-W
WP-LE3PC1004HL
WP-LE3PC1004HL
WP-201IC200-W
WP-B803-0-A-T
WP-D423-011-1010-HH-P-W
WP-S805-020-23-HL-P
WP-D823-011-0808-2H2L
WP-D8K11T08E040
WP-D816-01-08-HL
WP-8K11T08E000
WP-D807-01-08-HL
WP-D823-011-1212-2H2L
WP-8K11T12E020
WP-8K11T12E020
WP-D821-020-1212-HL
WP-D821-000-1212-N
WP-L801-00-A-N-P
WP-813T12E020
WP-LEQN111100HL
WP-B803-0-A
WP-C904-02-12-2H2L
WP-L802-01-FAG-HL-2P
WP-8K11T23E022P
WP-8K71T23E020P
WP-8K12T23E040PT
WP-C803-81-12-HL-P
WP-6222
WP-6214
WP-6035EX
WP-X803-0-A
WP-B803-0-A-W
WP-L901-00-F-N
WP-C803-01-12-HL-P
WP-S805-022-23-HL
WP-D935-060-1212-H
WP-C803-01-23-HL-P
WP-T803-02-12-HL-P
WP-C801-00-23-N
WP-C401-00-23-N
WP-C803-01-08-HL
WP-8036-EX
WP-8067-EX
WP-8012-EX
WP-C403-01-12-HL-W
WP-LC802-02-AAG-N-2P
WP-CTA1EJ501R1FD5G17/0-1MPa
WP-8A1S1R1F2A5G17/0-1MPa
WP-8K51T08E032-W
WP-D845-80-08-N-W
WP-L801-81-A-HL-P-W
WP-LEAVC600HLT
WP-8K-12-T23E042P
WP-L801-02-ANN-HL-P
WP-L801-02-ANN-HL-P
WP-8K-12-T23E022P
WP-8K-08-T23E022P
WP-B803-0-A
WP-R302C1601232000A
WP-B803-0-A
WP-D401-00-15-N-P-W
WP-D423-011-1010-HH-P-W
WP-6243
WP-302IC22-W
WP-D807-81-09-HN-K-P-T
WP-T835-022-2312-LR
WP-6012X
WP-LEAAC600HL
WP-C401-082-12-N
WP-B803-0-A-W
WP-C403-01-09-HL
WP-301DL22-I-W
WP-C803-01-03-HL
WP-D816-81-08-HH-T
WP-C803-81-10-HH-T
WP-D905-022-23-HL
WP-C303-07-08-HL
WP-C803-01-08-HL
WP-D816-81-08-HH-T
WP-D809-80-23-NN
WP-C401-00-23-N
WP-C903-01-23-HL
WP-DSAD01EP1C1S5/0-500Pa
WP-6047-EX
WP-B803-0-A-W
WP-D823-011-1212-2H2L
WP-KAS1G1F2A5G/0-1MPa
WP-S805-020-12-HL-P
WP-K1A1S1G1FEB5G/0-1.6MPa
WP-D423-011-1010-HH-P-W
WP-C903-01-08-HL
WP-D805-022-23-HL-P
WP-D805-020-23-HL-P-T
WP-L901-01-A-B-P
WP-D403-01-12-HH
WP-C801-00-12-N-P
WP-DR2AE22M1B3D0JS5/0-544Pa
WP-DP5E22M1B3D1JS5/0-100KPa
WP-6243
WP-T823-011-2323-2H2L-2P-T
WP-8K-71-T23E022-T
WP-8K-71-T23E022-W
WP-8K-13-T23E022P-W
WP-BDP3E22M3B3D0S2/0-3.5KPa
WP-T803-02-12-HL-P-T
WP-8K-12-T23E024P-T
WP-LEAVC600N-T
WP-D809-80-23-N
WP-C801-02-12-N-P
WP-LECJL1004N
WP-DR2AE22B3JS5/0-1000Pa
WP-K1A1I1G4FEA5G/-100-10KPa
WP-L804-00-FAG-N-2P
WP-201TR220-PT100-W
WP-LEAVC600HL-T
WP-D921-050-2323-NN
WP-D816-81-08-HL-T
WP-D805-87-08-HL-T
WP-C802-03-03-HL
WP-L801-01-A-HL-P
WP-D423-011-1010-HH-P-W
WP-D421-000-1816-NN-P-W
WP-D823-011-1010-HLHL-P-W
WP-D421-000-1515-NN-P-W
WP-C901-00-08-N
WP-C901-00-02-N
WP-C904-02-12-HHLL-P
WP-S835-020-1512-H
WP-B803-0-A-W
WP-S805-020-08-HL-T
WP-D823-011-1212-2H2L-2P-T
WP-S805-020-12-HL-T
WP-S805-020-12-HL-P-T
WP-C745-020-24-NN-T
WP-B803-0-A
WP-C403-02-23-HL-P
WP-S816-81-23-HL
WP-T835-010-1212-H
WP-101AC20-A-W
WP-8K-11-T23E000
WP-L802-02-AAG-HL
WP-R302C1600032000A
WP-C904-02-23-2H2L-P
WP-D923-011-0808-2H2L
WP-101AC20-A-T
WP-RLC801-20-A-NN-P-F
WP-D401-02-08-N
WP-L801-20-F-N-P
WP-D923-011-2323-2H2L
WP-C903-01-23-HL-P
WP-C903-01-23-HL
WP-201DL20-W
WP-D935-010-1212-H
WP-L802-02-FAG-HL-2P
WP-D805-020-12-HL-P
WP-301IC22-I-W
WP-8K-12T23E024P-T
WP-L801-02-A-HD-P
WP-L801-02-A-N-P
WP-L801-02-A-HL-P
WP-L901-00-A-N-P
WP-AKCS1P1F2A5GJ1
WP-D903-01-12-HL-P
WP-EMF-B3001C3EA10T53(200)
WP-K1A4S4G4FEB5G18G/0-1.6MPa
WP-LT5EA22DM1S5/0-3.8MPa
WP-LT5EA6A22DM1S5/0-13MPa
WP-K1A1S1G1FEA2G/0-40m
WP-LC1S3YA1F2A5H/0-5m
WP-D804-01-12-2H2L-P
WP-BGP7E22M1B3D0NS5/0-1.2MPa
WP-D905-022-23-HL
WP-T804-01-12-2H2L-P
WP-LEQT1K1E1
WP-L801-84-A-HL-2P
WP-LC803-02-AAG-N-2P
WP-LC803-02-AAG-N-2P
WP-D823-022-1212-2H2L-W
WP-D823-022-1818-2H2L-W
WP-DP5E22B3S5/0-200KPa
WP-ADP5J22B3S5/0-200KPa
WP-CTA1EJ501R1FD5G25GW/0-30MPa
WP-S845-020-23-HL
WP-T804-02-12-HLHL-P
WP-L801-01-ANN-HL-P
WP-C803-02-12-HL-P
WP-D807-02-08-HL
WP-C403-01-12-HL
WP-301DL22-I-W
WP-C804-02-12-2H2L-P
WP-LG1S1FA11F2A5H/0-3m
WP-D809-80-23-N
WP-K1A1S1G1FEB5G/0-2MPa
WP-8K-11-T12E000
WP-6113-EX
WP-K1A1S1R1F2A5/0-50KPa
WP-C803-01-23-HL-W
WP-8K-11-T08E022
WP-8K-11-T03E000
WP-8K-11-T03E020
WP-D821-000-0808-N
WP-D806-00-03-N
WP-8K-11-T12E022
WP-8K-11-T12E020
WP-8K-11-T12E021
WP-D821-000-1212-N
WP-8K-11-T08E020
WP-D821-000-1212-N
WP-D821-020-1212-N
WP-8K-23-T12E020-P
WP-TS805-020-12-HL-P
WP-LS803-00-AAG-N
WP-L801-00-A-N
WP-LS801-00-A-N
WP-LEAAC100N
WP-T835-010-1212-HL
WP-S835-010-1212-N
WP-B803-0-A
WP-9051
WP-201TR22-PT100-T
WP-301DL22-I-T
WP-D905-820-12-HL
WP-S403-01-23-HL
WP-C401-22-15-N
WP-L803-02-AAK-HL-2P
WP-C803-02-12-HL-P
WP-C803-01-03-HL
WP-S835-012-1212-HR
WP-C903-01-12-HL
WP-R80A1004009A/2611
WP-C803-02-12-HL-P
WP-D807-01-03-HL
WP-S435-020-1212-H-W
WP-LC801-00-ANN-P
WP-C903-01-23-HL-P
WP-C901/S801外殼
WP-BADP4I22M3B3D1D2/0-40KPa
WP-BADP3I22M3B3D1D2/0-6KPa
WP-C904-02-08-2H2L-P
WP-2448
WP-L801-20-F-N-P
WP-C804-02-23-2H2L-P
WP-S804-02-10H2L-P
WP-8AS1G4F2A5G/0-40MPa
WP-8A1S1G4F2A5G/0-0.5MPa
WP-C401-00-12-N-P
WP-C801-00-12-N-P
WP-K1A1S1G1FEC5G/0-1MPa
WP-TX805-020-23-HL-P
WP-T805-020-10-HL-P
WP-T823-022-2323-2H2L-2P
WP-D905-020-12-HL-P
WP-C403-02-23-HL-W
WP-C403-02-09-HL
WP-LEAVC102HHT
WP-LE3PC1023W
WP-302IC22-1212-W
WP-301IC20-12-W
WP-D821-000-0308-N
WP-8K-11-T12E020
WP-8K-11-T12E000
WP-8K-11-T12E000
WP-8K-23-T12E020-P
WP-T805-020-12-HL-P
WP-T835-020-1212-H
WP-S805-020-12-HL-P
WP-S835-020-1212-HL
WP-L801-02-A-N
WP-L801-00-A-N
WP-LEAAC100NT
WP-LEAVC100N
WP-B803-0-A
WP-KA1I1G1F2A5G/0-0.1MPa
WP-D809-80-23-N
WP-C403-01-12-HL-P
WP-L804-01-FAG-HL-2P
WP-D923-022-0303-HLHL
WP-D903-01-23-HL-P
WP-201DL22-W
WP-DS803-01-23-HL-P
WP-D705-070-23-HL
WP-201DL20-T
WP-C901-02-12-N
WP-B803-0-A-W
WP-8K-21-T08E022
WP-D806-00-23-N
WP-C803-01-23-HL
WP-TS803-02-23-HL
WP-LEHZC602NW
WP-D803-01-12-HL-P
WP-D803-01-12-HL-P
WP-D923-011-2323-2H2L
WP-D903-01-23-HL-P
WP-D903-01-03-HL
WP-C403-02-12-HL-P
WP-8K-11-T12E002P-T
WP-B803-0-B
WP-C803-01-23-HL
WP-C803-01-01-HL
WP-C803-01-12-HL-P
WP-C804-02-12-HL/HL-P

    WP-LCD系列智能儀表
    WP-天然氣流量積算儀
    WP-LED數字顯示控制儀/光柱顯示控制儀
    WP-LCD無紙記錄儀
    WP-LED雙回路數字顯示控制儀/光柱顯示控制儀
    WP-LCD-32段PID可編程控制儀
    WP-LED多路巡檢控制儀
    WP-LCD-PID自整定控制儀
    WP-PID自整定控制儀/PID光柱顯示控制儀
    WP-LCD-PID自整定控制儀（外給定或閥位控制）
    WP-PID自整定/光柱顯示控制儀（外給定或閥位控制）
    WP-LCD-多通道巡檢控制儀
    WP-LED手動操作器/光柱顯示手動操作器
    WP-LCD液位/容積控制儀
    WP-LED32段PID可編程序控制儀
    WP-LCD-NLQ智能化防盜型熱量積算記錄儀
    WP系列流量積算控制儀
    WP-LCD-智能化防盜型流量熱能積算記錄儀
    WP-LK系列流量積算控制儀
    WP-LCD-A/M手動操作器
    WP-LED-液位/容積控制儀
    WP-帶打印流量積算控制儀
    WP－LED智能電工儀表
    WP帶打印多路巡檢控制儀
    WP-LED交流/直流電工表
    WP-閃光報警控制儀
    WP-系列頻率/轉速表
    WP-閃光報警控制器
    WP-系列計數儀表
    WP-音響報警器
    WP-計數/計時顯示控制儀
    WP- 轉速/線速度顯示控制儀
    WP現場參量變送單元
    WP－壓力變送器
    WP-PID自整定控制記錄儀
    WP-智能防盜流量/熱能無紙記錄儀
    WP-LCD-智能化64路巡檢儀
    WP小型化配電器、隔離器
    WP系列模塊
    WP-單/雙路熱電偶/熱電阻溫度變送器
    WP-系列靜壓液位變送器
    WP-單/雙路電壓/電流轉換模塊
    WP－LC系列纜式靜壓液位變送器
    WP-配電模塊　
    WP－LR系列桿式靜壓液位變送器
    WP（雙路）數學運算模塊
    WP-LD系列直裝式靜壓液位變送器
    WP顯示模塊
    WP－系列隔膜式壓力變送器
    WP-壓旋式隔膜壓力變送器
    WP－多功能隔膜壓力變送器
    WP-小型化差壓變送